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SEPTEMBER 1926. Vol. LI. No. 606. THE ANALYST PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS AND OTHER ANALYTICAL CHEMISTS. Death. We regret to record the death on August 5th of Mr. Lester Reed Public Analyst for Croydon. Problems in Connection with Ancient Egyptian Materials. €31- A. LUCAS O.B.E. F.I.C. (Kent7 at the Meeting J m e 2 1926.) TT is only in comparatively recent years that the chemist has been consulted by the archaeologist and has been given an opportunity of examining antique objects, and lip to the present time little more than preliminary work has been possible and a considerable amount of detailed systematic chemical analysis still remains to be done. Antique objects are examined by the chemist for several reasons chiefly in order to furnish information concerning the materials of which they are com-posed so that they may be correctly described and sometimes so that they may be approximately dated but also to ascertain the nature of any change or deteriora-tion that has taken place so that suitable treatment may be applied and occasionally to detect forgeries.Since antique objects are composed of the same kinds of materials as the substances that an analyst in general practice deals with regularly and since the principles underlying the examination of these materials are well known it follows that whatever interest such objects may have in themselves or by reason of their antiquity there can be little that is new about the methods used in their examina-tion. I t is not proposed therefore to describe methods except incidentally, 43 436 LUCAS PROBLEMS IN CONNECTION WITH ANCIENT EGYPTIAN MATERIALS but rather to give an account of some of the unsolved chemical problems in connection with the materials.At the outset it should be remembered first that many antique objects are of such a kind that no sample whatever can be taken for analysis since this would injure or destroy the objects; second that even when sampling is permissible the amount of material available for analysis is generally very small; third that an object is not always in its original condition but may have suffered deterioration, resulting in considerable chemical change ; and fourth that frequently some exami-nation if only a preliminary one must be made on the spot with very few reagents and the simplest appliances.All these factors therefore condition and limit the nature and extent of the examination it is possible to make. As it would be impossible to discuss all the different kinds of material that from time to time present chemical problems for solution a few of the most important only will be briefly considered. Thcse arc flint implements faience, glass metals mortar and plaster oils and fats pigments and varnish pottery, resinous materials stone and textile fabrics ; these will now be separately described. FLINT IMPLEMENTS-These go back to Paleolithic and Neolithic times, periods so remote as to be quite undatahlc. Thc chemical interest in these im-plements lies in thc brown or black patina with which many of them are covered. This patina consists essentially of a mixture of oxides of iron and manganese in varying proportions and there is considerable difference of opinion regarding the source of these oxides the probability in my opinion being that they have been formed from compounds of iron and manganese contained in the flint and that when this was exposed on the surface of the ground and was regularly moistened by dew and occasionally by rain traces of iron and manganese existing in the ferrous and manganous conditions respectively were gradually dissolved and being drawn by capillary attraction to the surface became converted into a thin film of insoluble oxides by exposure and heat.If the time taken for these changes to occur could be cstimated even approximately this would prove of immense value to the archaeologist but any such estimate seems hopeless.FAImcE.-Faience is a product peculiar to Egypt and may be defined as glazed siliceous ware; it is composed of a body material covered with a coloured glaze. There is of course no difficulty in determining by the usual methods of chemical analysis the composition of either the body material or of the glaze, and the former consists of practically pure silica and the latter is a soda-lime-silicate. The problems in connection with faience are first what is the origin of the silica of the body material; and second in what manner was it held together while being shaped and glazed? A microscopical examination of thc material shows that it consists esscntially of angular particles of quartz that are undoubtedly the result of artificial crushing, and it is manifestly some form of powdered quartz but what particular form it is impossible to say.Crushed white siliceous sand seems one of the most likely substances to have been employed and would have been generally available; crushed quartz rock such as that occurring at Aswan would also hc suitablc LUCAS 1’KOULEMS IN CONNEC’I‘ION WITH ANClENT EGYL~TIAN MA’I‘EKIALS 437 but would take more labour to prepare and would only be available in one locality. I t was quartz however that at a very early date was fashioned into small objects, which were then glazed a practice from which the making of faience probably originated. Such a material as that described possesses no coherence whatever naturally, and the body of a faience object is generally so friable that it can readily be rubbed away with the fingers except in those instances in which the glaze has penetrated below the surface.How then was the material held together while being shaped and glazed? I t is frequently stated that a small proportion of clay sufficient to riiakc the material plastic was added but both chemical analysis and micro-scopical examination prove clay to be absent. Neither was gypsum the binding material,.since this also is shown by analysis to be absent. Fat gum and glue have all been suggested and in several specimens out of a large number examined there were a few small particles of black organic matter distributed throughout the mass which conceivably might have been the remains of some adhesive but the evidence was too slight to be in any way conclusive.In the case of one particular lot of small faience figures however all from thc same place there was a grey inner core surrounded by a zone of white. This grey core contained a number of black particles and there was little doubt that its dark colour was due to the presence of organic matter that had been partly burned. This was confirmed by strongly heating the specimens when the core became definitely lighter in colour though not entirely white. In those instances in which the glaze has penetrated the body material this now acts as a binder but manifestly it could not operate while the object was being shaped before the glaze was applied. That some a t least of the smaller faience objects werv moulded is proved by the finding of a large number of red pottery iiioulds in some of which were the remains of siliceous material.GLAss.-Glazc not only on faience which has just been described but also on quartz and on stcatitc was used in Egypt in archaic times that is before or about 3000 B.c. and it would seem a very simple step from glaze to glass since they arc both of the same composition and must have been made in the same way from the same materials the only difference between them being in the manner of use. glaze being always applied to the surface of an object whereas glass was used independently. The development from glaze to glass however took a very long time and it was not until about the beginning of the Eighteenth Dynasty, sonic 1800 years aftcr glazc was employed that glass came into general use.This date of the introduction or invention of glass is one of the most disputed points in Egyptology and objects of much earlier date are frequently claimed to be glass and it is riot only possible but probable that glass was made exceptionally and in small quantity for simple objects some time before its use became general. I t inight seem a very easy matter to ascertain whether an object was made of glass or not but it is not so easy as it appears at first sight. The objects in dispute are not vessels about which there could be little doubt but generally small pieces of inlay often in jewellery which naturally cannot be subjected to any analysis 438 LUCAS PROBLEMS IN CONNECTION WITH ANCl,EN’I‘ LGYf’I’IAN MATERIALS and can at most only’ be examined physically.The questioned material if not glass may be a glazed material such as glazed quartz or faience or it may be a natural stone probably not of normal quality or colour or possibly deteriorated. The only way of settling such questions is by careful inspection by means of a powerful lens or better a microscope. Ancient Egyptian glass is a soda-lime-silicate containing an excess of alkali and was apparently made from sand and natural soda (natron) the lime probably being an impurity in the sand. There was practically no colourless transparent glass, since glass was not required to transmit light. The white opaque glass owes its opacity to oxide of tin. The blue glass was generally coloured by a copper compound though occasionally with cobalt.The green was generally also coloured by copper though sometimes by iron. The yellow glass was sometimes coloured by lead and antimony and some-times by iron and manganese. The amethyst colour was produced by manganese, and the black by copper and manganese or sometimes by a large proportion of iron. The colour of ancient Egyptian glaze and glass frequently fades or changes; thus blue becomes whitc green turns brown and red becomes covered with ;L coating of green. Thc fading of blue to white is probably duc to thtl reductioii of the copper from the cupric to the cup-ous condition but why this should take place is not clear; green manifestly turns brown owing to the oxidation of the iron present and the change from red to green is caused by the formation of a cupric compound from the cuprous oxide present.A considerable amount of chemical work yet remains to be done on ancient Egyptian glass; thus although cobalt has been reported by several analysts others still deny that it was ever uscd. Again a knowledge of the dates at which certain colouring materials were ‘first employed would be valuable for it would not only help to date the glass but would also throw light upon Egypt’s intercourse with other nations as some of these colouring materials antimony and cobalt for instance must have been imported. METALS.-A large number of the earlier analyses of ancient Egyptian metal objects which have been made are practically useless. This is partly owing to the fact that many of the impurities occurring in small proportion were not deter-mined and partly because the objects have generally been corroded and often badly corroded and as corrosive influences never attack a metal and its con-stituents proportionately and uniformly it follows that a chemical analysis of such material cannot represent the original composition.With regard to the analysis of corroded metal or altcrcd material of any sort the analyst is confronted with a dilemma having three horns in place of the usual two. If he presents a complete and detailed analysis of the specimen as it reaches him he will almost certainly mislead the archaeologist; if he makes only a partial analysis he may omit to search for traces of various ingredients the presence or absence of which might supply valuable information; whilst if he attempts to explain his results he will almost certainly go astray unless he knows the con-ditions under which such materials occur both naturally and artificially and unless he has some knowledge of archaeology.The red glass was coloured by cuprous oxidc. LUCAS PROBLEMS I N CONNECTION WITH ANCIENT EGYPTIAN- MATERIALS 439 All analyses are made with some ulterior motive and not merely in order that the chemist may exercise his ingenuity his manipulative skill or his chemical knowledge nor even in order that he may produce a series of figures for con-templation in his spare moments or in his old age. In the case of antique metal objects the motives are first to identify the metal and second to know the nature and extent of the impurities present as these may throw light on the locality where the ore or metal originated and the mode in which these have been treated.These points may usefully be considered with respect to specific cases. CoPPER.-Copper was used in Egypt in Predynastic times that is before 3400 B.c. a t first for ornaments and small objects and later for weapons and tools, and it would be of value to know definitely where this copper came from. I t is well known that ores of copper occur in the eastern desert of Egypt between the Nile and the Red Sea and also in Sinai and it is also known that both these sources were exploited a t a very early period the Sinai mines certainly dating from the First Dynasty that is before 3000 B.c. and being used until the Twentieth Dynasty (1200 to 1090 B.c.); but about the mines in the eastern desert little is known beyond the fact that they Show signs of ancient working.It is possible that the ores from the two localities might have notable differences of composition in respect of the nature of the impurities present but unfortunately detailed analyses of these ores have never been made. It is known too that from the Eighteenth Dynasty onwards copper or copper ore was imported into Egypt, especially from Syria and Cyprus and it might help to date an object if such copper could be differentiated from Egyptian copper. A few ancient Egyptian copper objects have been found on analysis to contain a high proportion of arsenic namely 2.3 3.9 and 5.6 per cent. respectively and in a few instances bismuth has been found varying up to about one per cent.Those who maintain that the Egyptians must have had some mysterious process for hardening copper the secret of which has been lost or otherwise they would not have been able to work the hard stones they certainly did work see in the arsenic and bismuth referred to a confirmation of their argument but analysis of the ores used would probably show these to be highly arsenical and in some cases to contain bismuth and thus the arsenic and bismuth would be accounted for naturally. Moreover although arsenic in the form of sulphide was used as a pigment it was only at a comparatively late date and there is no evidence that compounds of bismuth were ever known. Owing to the lack of a large series of chemical analyses of metal objects from the earliest periods there is no certainty about the date when bronze was first employed in Egypt; it was however known and used in the Twelfth Dynasty (about 2000 to 1788 B.c.) but whether earlier or not is doubtful.BROwE.-Bronze certainly did not originate in Egypt as tin ores do not occur in the country and therefore at first it must have been imported but it is always assumed that it was subsequently made in the country from native copper and imported tin and although very probable there is no proof of this. Chemical analysis however might furnish such proof. The earliest references to tin in th 440 LUCAS PROBLEMS IN CONNECTION WITH ANCIENT EGYPTIAN MATERIALS ancient records and the earliest objects made of tin both date from the Eighteenth Dynasty which would suggest that tin was not known in Egypt before that time.We are ignorant too of where and how bronze was first made though this must have been in some locality where copper ores and tin ores occurred in close proximity to one another or where a combined copper and tin ore occurred an accidental mixing and smelting of the former or an accidental smelting of the latter producing bronze and it is reasonable to suppose if such an accident happened several times that the superior qualities of the resulting metal compared with copper, namely the lower melting point and the greater hardness would not escape notice and that the operation would then be deliberately repeated. But which of the two possibilities actually happened? It seems improbable that the combined ore of copper and tin namely stannite or tin pyrites was used; first because it occurs only in small quantity and in a few localities; second because the principal and most important ore of tin is the oxide cassiterite or tinstone which does not contain copper; third because if a combined ore had ever been employed its use would have continued for at least some time and in the then very elementary and purely empirical condition of metallurgy it could never have led to the use of the artificial mixture of the two ores of the employment of which at a later period there seems no doubt as there would have been no knowledge of the connecting link between the two; and fourth because from the combined ore it is not likely that tin would have been produced as it certainly was produced probably not so early as bronze but certainly later.The small proportion of sulphur present in the bronze is also an argument against the use of a sulphide ore. A two-fold discovery of bronze once from the naturally-combined ore of copper and tin and once from an artificially-made mixture of the separate ores is most improbable. GoLD.-Gold was used in Egypt as far back as Predynastic times that is, before 3400 B.c. and as the metal occurs abundantly in the country both in the alluvial form and in quartz rock there can be little doubt that the early gold was obtained locally. At a later date however gold was brought into Egypt from abroad both as tribute and as one of the spoils of war and it might help to date an object if this imported gold could be differentiated from native Egyptian gold, and manifestly the only way of doing this would be by chemical analysis.It might be found however that in some cases the gold was Egyptian in origin and had merely returned from abroad in the shape of worked objects. One well-known Egyptologist has already attempted to distinguish foreign gold from Egyptian gold in this manner but as his data were incomplete his conclusions were wrong. Thus he has stated that certain gold from Egyptian tombs must be of Asiatic origin because it contains a considerable proportion of silver being evidently unaware that practically all gold when found contains silver and that Egyptian gold often contains more than 20 per cent. of silver. Another question to be settled by chemical analysis is whether the ancient Egyptians refined gold and if so at what date and also a t what period did they begin to debase gold.From the few analyses available it would appear as if gold were not refined and yet the ancient records mention fine gold " gold of two times LUCAS PROBLEMS IN CONNECTION WITH ANCIENT EGYPTIAN MATERIALS 441 and " gold of three times," which suggest refining. There is no doubt however, that gold was debased as the proportion of copper it sometimes contains is too high to be natural. SILVER.-with regard to silver the important question is whence came the early silver used in Egypt? This metal was employed in small quantity from Pre-dynastic times but it was not until the Eighteenth Dynasty that it was much used, and it was not until Ptolemaic and Roman times that it became plentiful.At these later periods however it was certainly imported. So far as is known silver ores do not occur in Egypt though silver is found in all Egyptian gold and the Egyptian lead and nickel ores contain a very small proportion of silver. Only a few analyses of ancient Egyptian silver objects are recorded and these show gold to be present in proportions ranging from 3.2 to 14.9 per cent.; and since it is highly improbable that the metallurgical knowledge of the ancient Egyptians was sufficiently advanced a t the early date at which they first used silver to enable them to separate this metal from gold even imperfectly, and still more improbable that they even knew of the presence of silver in the nickel and lead ores much less that they could separate it a possible explanation of the early silver is that it was gold so rich in silver as to have a white colour; and although no such gold is known in the country a t the present time it is suggested that it may have occurred and may have been worked out or may still occur and may have escaped notice in modern times.Such a metal would indeed be "white gold," which is the meaning of the ancient Egyptian word for silver. In this connection may be mentioned the light yellow-coloured natural alloy of gold and silver that occurs in Egypt and was used anciently; it was called eZectron by the Greeks and electrum by the Romans on account of its resemblance in colour to amber the Greek name for which was electron; electrum being the term now used.According to analyses of electrum that have been made the proportion of gold varied from 72.1 to 85.9 per cent. and that of silver from 11.3 to 22.3 per cent. Electrum may be regarded as a half-way stage between gold and silver and its occurrence in Egypt increases the probability of the occurrence of an alloy still richer in silver which could be called "white gold." MORTAR AND PLASTER.-Both the mortar and plaster of the ancient Egyptians were one of two materials namely either gypsum or clay and so far as can be ascertained lime in any form or for any purpose was unknown in Egypt until the time of the Roman occupation. This was probably due first to the scarcity of fuel in the country since limestone is even more abundant than gypsum and more easily accessible; and second to the dry climate which permitted the use of gypsum for outdoor use.The scarcity of fuel naturally led to its economical use and the much lower temperature required to burn gypsum compared with that required for lime namely from 100" C. to 200" C. (generally about 130" C.) in the first case, and about 900" C. in the second case makes a considerable difference in the amount of fuel used. There is of course no difficulty in the chemical analysis of mortar or plaster, but serious errors have been made both by chemists and archaeologists in thei 44.2 LUCAS PROBLEMS I N CONNECTION WITH ANCIENT EGYPTIAN MATERIALS interpretation of the analyses with the result that the literature of archaeology is full of mistakes about the composition of these materials.This arises from the presence of calcium carbonate and of siliceous sand which are usually attributed to artificial admixture with lime that has become carbonated and with sand respectively. Calcium carbonate and sand however are natural impurities, both in Egyptian gypsum and in clay and are not artificial additions and they therefore occur in the mortar and plaster made from these materials. One interesting point about ancient gypsum mortar and plaster is the pink colour which they sometimes assume. This is purely a surface coloration and appears to be due to an iron compound though it is not the red of ferric oxide, but a decided pink. OILS AND FATs.-Although fatty matter has frequently been found in Egyptian tombs it has seldom been analysed and of the few analyses made none is con-clusive.This is almost inevitable as oils and fats unless kept under special air-tight and sterile conditions which is not the case when placed in jars in tombs, sooner or later decompose and as some of the bodies formed escape either by evaporation or by soaking into the material of the containing vessel all that the analyst has for examination is merely a portion of the products of decomposition. What is left consists of a mixture of fatty acids and it is only by the separation, purification and identification of these and by a determination of the proportion in which each occurs in the mixture that the nature of the original oil or fat can be known and since what remains is generally a portion of that formed and not necessarily a representative portion the problem may often be insoluble.The fatty matter often smells like rancid coconut oil or like rancid butter and occasionally of valeric acid and the fatty acids identifiable are generally palmitic and stearic acids and less frequently oleic acid and in one instance calcium butyrate was found. When the fatty acid consists essentially of stearic acid alone it seems justifiable to assume that the originalmaterial has been castor oil, which was well known to the ancient Egyptians and which is one of the few oils or fats that contain little or no palmitic acid. When the fatty acids consist of stearic and palmitic acids in almost equal proportions it is possible that the original material was an animal fat such as ox fat. There is however as will be realised, considerable scope for further chemical work on the subject.PIGMENTS AND VARNISH.-The ancient Egyptian pigments have often been analysed and their nature is well known; most of them are naturally-occurring mineral substances. The white is generally calcium carbonate but occasionally calcium sulphate. The black is carbon being sometimes soot and sometimes a coarser material, possibly powdered charcoal. The black pigment is very prone to disappear more so than any other pigment but the reason for this has not been investigated; it cannot however be due to fading. The grey is a mixture of black and white. The red is red ochre sometimes natural and sometimes produced by calcining yellow ochre. In Roman times however both red lead and madder on a base of gypsum were also used.There are two A similar colour is also sometimes found on limestone. The browns are all natural iron oxides LWCAS PROBLEMS I N CONNECTION WITH ANCIENT EGYPTIAN MATERIALS 443 yellows the common one (that employed a t the earliest date) being yellow ochre, and the other being sulphide of arsenic (orpiment). The earliest blue was azurite, a naturally-occurring basic carbonate of copper but the principal blue was a most remarkable artificial compound consisting of a crystalline copper-lime-silicate in the condition of a frit. The composition of this has been investigated by many chemists beginning with Sir Humphrey Davy in 1815 and both Dr. Russell and Messrs. Laurie McLintock and Miles have not only analysed the frit but have also reproduced it.Another blue recorded as having been used is cobalt but this I have never found myself. There is however need for further systematic work to ascertain at what periods the various blues were introduced. The earliest green pigment was powdered malachite a basic carbonate of copper that occurs abun-dantly in the country but a t a later date a green frit analogous to the blue frit just described was used instead. One interesting fact about which there seems no doubt although I have not been able to verify it personally is that in some few instances a blue pigment has corroded the gypsum plaster on which it was painted and in one case a pigment, that was probably blue has corroded wood in such a manner that what were painted inscriptions are now merely a series of holes in the wood looking almost as though they had been burned.So far I have not been able to find any satis-factory explanation for these phenomena. Although the ancient pigments are well known the nature of the medium or vehicle with which they were employed has never been satisfactorily established. There is no evidence whatever of the use of oil even as late as the Graeco-Roman period at which date painting was done by the encaustic process that is by mixing the pigments with melted beeswax and it seems most probable and is generally accepted that the medium was water mixed with some binding material such as gum or glue both of which were well known a t the time and the best chance of determining which was employed would be by the analysis of paint mixed ready for use if this could be found.There should be no difficulty in detecting either gum or glue if present. The use of white of egg seems improbable since the domestic fowl and hence the ordinary egg is not indigenous to Egypt but was introduced into the country a t a late date. Tests for albumin too would probably be useless as this is likely to have become denaturalised. Glue has been reported as having been found on painted surfaces on several occasions but this is no proof that it was mixed with the paint and it may well have been used to prepare the surface for painting in the manner of modern size. Two kinds of varnish were largely employed in ancient Egypt one now yellow or reddish but originally colourless or practically colourless which was used to cover painting on wood, and very occasionally painting on plaster and the other black used exclusively for coating certain wooden funerary objects without any painting below.Both these varnishes consist of resin and the problem concerning them is the manner in which they were applied. In present-day varnishes the resin is dissolved in boiled linseed oil turpentine alcohol or other solvent but it is believed that all such solvents were unknown in ancient Egypt. There is no evidence either o 444 LUCAS PROBLEMS I N CONNECTION WITH ANCIENT EGYPTIAN MATERIALS the presence of oil and the varnish is insoluble in turpentine though freely soluble in alcohol. Strong wine has been suggested as a possible solvent but even in the strongest wine resin is not sufficiently soluble to produce a varnish.The alter-native therefore seems to be a resin that did not require an extraneous solvent, which means a naturally-occurring resin already in the liquid form such for ex-ample as an oleo-resin. Oleo-resins however although nominally liquid are, at the best of a thick syrupy consistence too viscous to admit of application as a thin coating though this viscosity may be reduced by warming. A natural oleo-resin applied warm therefore seems a possible explanation. Another suggestion that has been made is that the resin was applied in a finely-powdered condition, and was then liquified by means of heat but this does not appear very feasible. POTTERY.-BY pottery is meant ware made from clay moulded into shape while wet and then hardened by being baked.The chemical analysis of pottery is practically never required by the archaeo-logist but there is one interesting problem in connection with ancient Egyptian pottery that has not yet been satisfactorily solved namely the nature of the black colour of the Predynastic black and black-topped pots. This black colour which penetrates throughout the thickness of the ware has been accounted for in three different ways; first by the action of smoke from the fire used in baking the pots or of some volatile organic matter that would carbonise such as tarry matter from the fuel; second by the production of black oxide of iron by limiting the air supply during baking by covering with ashes that part of the pot intended to be black; and third by the application of a black colour to the pot.The first is the usual explanation and is supported by a certain amount of evidence both chemical and experimental. The second solution is very attractive from a chemical point of view and a production of black oxide by using a limited air supply is theoretically possible though a t present it lacks proof. The third method has actually been proved to have been used for certain types of pottery the black colour being produced though only that on the outside by the use of graphite. The whole subject needs further work both chemical and experimental before it can be definitely settled. RESINOUS MATERIALS.-Ahhough Egypt is not now a resin-producing country, and probably never was yet resin and resinous materials have always been largely employed.An early use of resin was in connection with burial and lumps of this material have often been found in graves of the Archaic period. At a later date both resins and gum-resins were employed in the process of mummification, and the latter also largely as incense. Resin too was used as an adhesive both by itself and also mixed with whiting and its use for varnish has already been mentioned. Occasionally too resin was fashioned into small objects such as beads and scarabs and even the pupils of the eyes in statues were sometimes made of resin. In the literature of Egyptology there are many precise statements regarding the nature of the resins used in ancient Egypt very few of which rest on the certain knowledge that can only come from systematic chemical examination an LUCAS PROBLEMS I N CONNECTION WITH ANCIENT EGYPTIAN MATERIALS 445 most of which are merely guesswork since the nature of these resins has been very little investigated and very few of them having been scientifically identified.This is largely due to the fact that many of them are probably of kinds that are not only not used but are not even known a t the present day. One analyst who has examined these resinous materials identifies a large number of different resins in each specimen; thus in one sample storax mastic and Aleppo resin are all positively identified and two other unknown resins are stated to be present whilst Chios turpentine and cedar resin are also thought to be probably present; in another specimen of material storax three different unknown resins a gum or gum-resin and a balsam were all found.This is quite contrary to my experience and excluding incense which is probably a mixture, the resins are usually homogeneous bodies of well defined character and where there has been any admixture it has been with natron or fatty matter. This analyst by well-known chemical means such as solution and precipitation separated certain bodies of which he made an ultimate analysis determining the carbon and hydrogen directly and the oxygen by difference. When however the smallness of the sample taken for analysis (from 0.02 to 0.22 grm.) the multiplication and division of the original figures necessitated by the calculations and the fact to take one example that 77.4 per cent. of carbon and 10.4 per cent.of hydrogen represent one substance and 77.3 per cent. of carbon and 10.2 per cent. of hydrogen a totally different substance one may be pardoned for thinking there is room for a mistake in identification. In several instances too this analyst bases a probable identification upon the smell of the substance or upon a process of exclusion, assuming that because negative results were obtained when certain specific resins were tested for and hence were probably absent that therefore another resin that it was thought might have been used was probably present. Among the former is a resin from some species of pine that has a slight fragrant smell and gives the Liebermann-Storch colour reaction and among the latter is myrrh. This is about all that can be definitely stated and there is therefore need for much work on the subject.USE OF BITUMEN.-Certain classical and early Arab writers state that bitumen of Judaea was used by the Egyptians in embalming and most Egyptologists and modern writers on mummification have followed this old tradition and without any evidence save that many mummies are black definitely state that bitumen or mineral pitch was used. Although the use of bitumen about the Ptolemaic period is probable no definite evidence of it has yet been found. The analyst previously mentioned states that he found bitumen in all the specimens of mummy material he examined but his identification is based on the fact that a tiny residue of black material obtained in the course of the analysis smelled somewhat like bitumen and contained sulphur.This same analyst however finds bitumen in ancient Egyptian perfumes. The use of a very small proportion of bitumen with a complex mixture of different resins or its use in perfumes seems most improbable. Al-though mineral pitch has not been found wood pitch has been identified on several The resins used may be divided into true resins and gum-resins 446 LUCAS PROBLEMS IN CONNECTION WITH ANCIENT EGYPTIAN MATERIALS occasions. It may be mentioned that these ancient resins frequently become dark brown or black and that mummy flesh becomes dark brown and very resinous-like and behaves very like resin when treated with solvents. COLOUR OF MUMMY HAIR.--In connection with mummies the colour of mummy hair may be mentioned. Hair is very resistant to decomposition but it is generally stated that the colour is not so resistant and even that all hair eventually becomes red owing to the disappearance of the colouring matter originally present and the oxidation of the iron compounds in the hair.As an example of this colour change, Petrarch is cited. Petrarch died at the age of seventy but from the age of twenty-five his hair was white and it is recorded that many years after his death his coffin was broken open by robbers in the hope of finding treasure and that the hair was then red. In the case of Egyptian mummies I have been unable to find any evidence of any change to red though in a few instances the hair is flaxen and suggests @st mortem bleaching due to the natron bath and in one case the hair had been dyed red probably by the use of henna.SToNE.-The chief purpose to be served by the examination of stone is to identify it in order that it may be correctly described. This is essentially a matter for the petrologist or for the petrologist and chemist working together but in the absence of a petrologist or geologist the chemist is often called upon to identify stone. It is very seldom that a chemical analysis of stone is necessary the only examination usually required being a critical inspection both with the naked eye and with a lens an approximative determination of the hardness by ascertaining whether it can be scratched with a knife and whether it will scratch glass some-times the determination of the specific gravity and in cases of special difficulty the microscopic examination of the powdered material or better of a thin section, and above all the comparison of the specimen with one of which the identity is well established.Occasionally a drop of acid may be required to confirm say, the distinction between calcite and gypsum. As an example of the confusion existing in the matter of the nomenclature of stones it may be mentioned that there is still discussion whether the material always called " alabaster '' in Egyptology and which chemically is calcium car-bonate is calcite or aragonite. Here the most useful test is the determination of the specific gravity that of calcite being 2.7 and that of aragonite 2.9. Other mistakes frequently made are in the recognition of the various green stones used in ancient Egypt among which are malachite beryl green felspar, green jasper green quartz and green chalcedony and the confusion in the literature is considerable.The archaeologist too is inclined to call all dark-grey or black stone if of coarse texture granite and if of fine texture basalt; and although basalt was used much of what is called basalt is a fine-grained crystalline schist. TEXTILE FABRICS.-There are many points of interest in connection with ancient Egyptian textile fabrics which for burial purposes were always linen, namely the method of retting and preparing the flax as also the methods of weaving and dyeing but I propose to confine myself to one aspect i.e. the natur LUCAS PROBLEMS I N CONNECTION WITH ANCIENT EGYPTIAN MATERIALS 447 and cause of the disintegration these fabrics have often undergone during their prolonged sojourn in the tombs.In some cases old Egyptian linen is in as good condition when found as when it was made whilst in other instances it is discoloured and rotted and may even be reduced to the condition of a black powder. The date of the burial apparently is not a factor in the problem and light which is known to rot textile fabrics may also be eliminated from the question as none of the fabrics were exposed to light while in the tomb. -The determining factors are damp and a certain amount of air and it is suggested that the damage is caused largely or wholly by fungi which induce a sort of slow spontaneous combustion. DISCUSSION. The PRESIDENT in thanking the author for his most interesting paper said that he did not know whether he ought to feel sad or glad at hearing that chemists were now being consulted as he felt that they should have been consulted long ago.I t was however a happy chance that Mr. Lucas should have been the man on the spot when a chemist was eventually consulted. He enquired whether there was any outstanding example of a disclosure of a method of doing something we did not know before; one was accustomed to hear much of the Egyptians’ inimitable ingenuity and of their lost arts yet Mr. Lucas seemed to indicate that there was nothing really inimitable after all. He was interested in the remarks about the condition of the fats found in the tombs and he suggested that the analytical figures might be compared with those on record in THE ANALYST (1907 32 89) for Irish bog butter.It was the custom in Ireland to preserve butter by burying it in the bog (peat) and specimens, which had been found after many years had been analysed and had afforded interesting information as to the decomposition of the fat. Miss M. A. MURRAY explained that she was speaking as an Egyptologist and not as a chemist. She had been trained by Prof. Flinders Petrie who was the first to realise the importance of chemical analysis in connection with Egyptology. She herself had had many analyses made and regarded them as valuable. Following Professor Petrie’s system of dating she contended that flint implements had been discovered which were in existence before 5000 B.C. Experi-ments had been made with a view to assessing the length of time required for patination but so far without success.It would first be necessary she thought, to arrive at the approximate date of the implements. As there was now some possibility of determining the date of the later palaeolithic implements she hoped that in due course the earlier palaeolithic specimens would also be dated and that, ultimately useful information would be obtained with regard to patination. Reviewing the various classes of substances mentioned by the author Miss Murray pointed out that the Ashmolean Museum was in possession of a glass bead of the first dynasty which Prof. Sir Henry Miers had identified by a specific gravity test; also an inlay of glass on a piece of ebony. Coloured glazes were not in general use until the end of the eighteenth dynasty, after the Syrian conquest; though before that time all shades of blue and green had been used together with a little black (manganese).Speaking of metals Miss Murray said that the early Egyptians used malachite for medical purposes-covering the under eyelid with green paint which protected the eye from the white glare off the ground; malachite was imported as it did no 448 LUCAS PROBLEMS IN CONNECTION WITH ANCIENT EGYPTIAN MATERIALS occur in the Nile valley. There was a “pilgrim bottle” from Egypt in the Ash-molean Museum made of tin. An analysis of the gold leaf covering of a coffin of the twelfth dynasty revealed that it contained 97.5 per cent. of gold. Castor oil was common in Egypt and was probably used for lamps as it has been so used in India till recent times.Giving a white light without smoke it was used for lighting up the tombs. With regard to perfumes she suggested that the scent was extracted with dilute alcohol by putting the scent-bearing leaves in fat and adding wine. The possibility of the use of egg albumin for the fixation of pigments had been suggested but there were no fowls in ancient Egypt nor did they arrive in the West until the days of Alexander the Great who introduced them from India. Evidence that the ancient Egyptians distilled alcohol was supplied by the representations of stills. A resin had been found which was described as amber; how did it compare with a genuine sample ? With regard to minerals it was known that salt and quicklime with a little alum were in use for mummification in the twelfth dynasty, Pottery of the prehistoric periods was often covered with a wash of ground haematite and then fired.Often the vases were placed mouth downwards in the ashes on the floor of the kiln thus excluding the oxygen during the firing. On the parts so covered the haematite became black i.e. formation of oxide (?). All the Egyptian amulets in the Ashmolean Museum a t Oxford were identified as to material by Sir Henry Miers by their specific gravity and microscopical appearance. Dr. PLENDERLEITH considered that the brown colour of flint implements was due to oxide of iron. He referred to samples of pre-Stonehenge implements which, although purple in the centre had turned white on the outside. Their age was unknown nor was it exactly known why the colour had changed; yet the effect of caustic soda on the blue was to turn it white ammonia having no effect.Had the author come across white patination in the Egyptian world? It had been suggested that faience was sometimes made from glazed sand-stone rather than from free sand when sand was employed. Another suggestion was that it was held together by some such substance as sodium silicate but, personally he attached more importance to the disc of carbon that had been found in the core. With regard to fats he mentioned that Mr. Chaston Chapman and he had been examining a cosmetic found in the tomb of Tutankhamen which had a coconut aroma and consisted largely of saturated fatty acids. They had been unable to identify the sweet smell which reminded them of “open broom blossom in the sunlight.” Vegetable fibre had been found in one fat recently analysed.Mr. A. CHASTON CHAPMAN said that the Tutankhamen cosmetic appeared to resemble very closely in appearance the specimen which the author had exhibited. It contained chiefly stearic and palmitic acids together with a smaller quantity of some lower saturated fatty acids (chiefly myristic) and about 30 per cent. of the so-called “oxidised ” acids. An interesting point was that after so long a period of time 6 per cent. of the glycerin should have remained undecomposed. The reason of course was that the fat.was sterile and there was not any evidence of bacterial decomposition. Sterols were absent but so far as could be stated the cosmetic appeared to consist of about 90 per cent.of some animal fat with about 10 per cent. of a fragrant resin or balsam. The coconut smell was almost certainly due to the oxidation products formed during the process of time and did not appear to have any connection with coconut oil. What strength of alcohol was required to dissolve resin LUCAS PROBLEMS I N CONNECTION WITH ANCIENT EGYPTIAN MATERIALS 449 Dr. H. P. STEVENS asked whether the fibre used was entirely linen. Also, did the author suggest that modern glass free from manganese would change colour in the sun or did he imply that the darkening was due to the presence of traces of this metal? The carbon core in faience he suggested might be due to the fact that the original wooden centre had been covered with an alkaline copper salt, which by solvent action had brought' about decomposition of the wood.Mr. C. A. MITCHELL referred to some sequins of red gold which the author had sent to him for examination. The bright red surface deposit on these contained traces of iron and he asked whether there was any evidence to show that the colour had been intentionally produced with the aid of an iron compound or whether it was accidental. He also mentioned a piece of graphite given to him by Sir Flinders Petrie. This dated back to about 1500 B.C. (cf. ANALYST 1922 47 380) and he asked the author whether any other discovery of ancient graphite had been made in Egypt. Dr. J. J. FOX stated that the colour of a specimen of black pottery examined by him was due not to carbon but to the reduction of oxide of iron to a lower oxide.Speaking on the disintegration of fats he referred to a specimen of beeswax, 600 years old the constants of which even after long exposure in a museum had remained normal. Mr. HARDING asked whether there was any indication of the use of lead in glazes prior to Roman times; and whether antimony was responsible for any of the yellow tints. Mr. LUCAS replying said that he was acquainted with the inlay mentioned by Miss Murray but that although manifestly a vitreous material it was not necessarily glass and might conceivably have been faience glazed on one side only from which the siliceous body material had been removed or had fallen away. Malachite occurred in Egypt both in Sinai and in the Eastern desert.Referring to castor oil he mentioned that the oil described by Herodotus as being used for temple lamps was apparently castor oil to which salt was added to prevent smoking. The beer was possibly very similar to the booza used a t the present day both in the Sudan and in Egypt, among the Nubians. It resembled thin gruel in appearance and generally con-tained about 8 per cent. of absolute alcohol. It had not been proved that the Egyptians of the eighteenth dynasty separated alcohol by distillation from either beer or wine. There was no evidence that amber was known in ancient Egypt until a late period the material so frequently termed amber being an entirely different resin. Although aluminium compounds and calcium carbonate had been found associated with mummies this in no way proved that alum and quick lime were used in mummification.The aluminium compound was not in the form of sulphate and other compounds e.g. the silicate were widely distributed. Calcium carbonate, too occurred extensively in Egypt and the mummy referred to came from a limestone district and both during mummification and burial and particularly during exhumation it would have been difficult to avoid contamination with calcium carbonate. With regard to myrrh this material was certainly employed in ancient Egypt possibly as suggested for making incense; it was undoubtedly used in mummification. The fibres used by the ancient Egyptians included wool as well as linen but wool was not used for burial purposes before Christian times; ramie fibre had also been reported on one occasion. Silk and cotton were not used until a very late period. Both beer and wine were well known in ancient Egypt 450 HAMID THE DETERMINATION OF POTASSIUM So far as was known lead glaze was not used in Egypt before Arab times. The formation of the amethyst colour only occurred in glasses containing manganese. Referring to Mr. Mitchell’s observations Mr. Lucas said that gold from Egyptian tombs was not always yellow in colour but often various shades of red, due sometimes to chemical changes in the traces of impurities in the gold and sometimes to organic matter on the surface. The very remarkable pink colour referred to however was very different; it was intentional and not accidental, and so far as had been ascertained seemed to be due to a trace of iron and might possibly have been produced by the use of an iron compound with subsequent heating. The lump of graphite analysed by Mr. Mitchell was the only piece that had yet been found in ancient Egyptian graves though graphite had been found in graves in the Sudan. Small amounts of graphite occurred in the gold-bearing quartz of Nubia but it was otherwise unknown in Egypt

ISSN:0003-2654    

DOI:10.1039/AN9265100435

出版商:RSC    

年代:1926

数据来源: RSC

摘要:

142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent.shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent.of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent.of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent.of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid). (47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent.of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight. Tea dust shall not yield over 5 per cent. of ash insoluble in water.Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat.The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent.of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent.of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent.of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent.of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D.G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat.(46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid). (47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent.of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight. Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent.of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.

ISSN:0003-2654    

DOI:10.1039/AN9265100450

出版商:RSC    

年代:1926

数据来源: RSC

摘要:

142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent.shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent.of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent.of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent.of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid). (47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent.of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight. Tea dust shall not yield over 5 per cent. of ash insoluble in water.Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat.The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent.of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent.of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent.of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.

ISSN:0003-2654    

DOI:10.1039/AN9265100453

出版商:RSC    

年代:1926

数据来源: RSC

摘要:

142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent.shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.

ISSN:0003-2654    

DOI:10.1039/AN9265100455

出版商:RSC    

年代:1926

数据来源: RSC

摘要:

142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent.shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent.of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent.of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent.of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid). (47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent.of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight. Tea dust shall not yield over 5 per cent. of ash insoluble in water.Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat.The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.

ISSN:0003-2654    

DOI:10.1039/AN9265100456

出版商:RSC    

年代:1926

数据来源: RSC

摘要:

142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent.shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent.of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent.of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent.of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid). (47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent.of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight. Tea dust shall not yield over 5 per cent. of ash insoluble in water.Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat.The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.

ISSN:0003-2654    

DOI:10.1039/AN9265100457

出版商:RSC    

年代:1926

数据来源: RSC

摘要:

142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent.shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent.of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent.of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent.of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid). (47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent.of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight. Tea dust shall not yield over 5 per cent. of ash insoluble in water.Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat.The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent.of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent.of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent.of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent.of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D.G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat.(46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid). (47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent.of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight. Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent.of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.

ISSN:0003-2654    

DOI:10.1039/AN9265100458

出版商:RSC    

年代:1926

数据来源: RSC

摘要:

142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent.shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.

ISSN:0003-2654    

DOI:10.1039/AN9265100462

出版商:RSC    

年代:1926

数据来源: RSC

摘要:

142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent.shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent.of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent.of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent.of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid). (47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent.of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight. Tea dust shall not yield over 5 per cent. of ash insoluble in water.Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat.The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.

ISSN:0003-2654    

DOI:10.1039/AN9265100463

出版商:RSC    

年代:1926

数据来源: RSC

摘要:

142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent.shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent.of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent.of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent. of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent.of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid). (47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent.of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight. Tea dust shall not yield over 5 per cent. of ash insoluble in water.Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent. of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat.The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent.of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.142 ABSTRACTS OF CHEMICAL PAPERS milk-solids-not-fat and 3.25 per cent.of milk fat, and in the reductase test (see Section 42) shall require at least 4 hours to decolorise the methylene blue solution. Cream must contain at least 40 per cent. of milk fat. (46) Butter.-Butter shall contain at least 80 per cent. of milk fat, and not more than 16 per cent. of water or 20 grains per lb. boron preservative (calculated as boric acid).(47) Cheese.-Cheese shall contain not less than 50 per cent. of milk fat on the dry substance, and skim-milk cheese not less than 10 per cent. (48) Tea.-Tea shall yield between 4 and 7 per cent. of ash (at least one half of which is water-soluble) and at least 30 per cent. of extract, which shall be determined by boiling 2 grms. of tea in 200 C.C. of distilled water under a reflux condenser for 1 hour, filtering hot, cooling and evaporating an aliquot portion to constant weight.Tea dust shall not yield over 5 per cent. of ash insoluble in water. Cofee.-Coffee shall contain not less than 10 per cent. of fat, and more than 1 per cent. of saccharine matter, and shall yield not more than 6 per cent. of ash, of which not less than 75 per cent. shall be soluble in water. Co$ee essence shall contain not less than 0.5 per cent.of caffeine. Cocoa.-Cocoa paste, mass or slab, is the solid or semi-solid mass pro- duced by grinding cocoa nibs, and shall contain not less than 45 per cent. of cocoa fat. The dry fat-free residue shall not contain more than 19 per cent. of natural cocoa starch, 6-33 per cent. of crude fibre, 8 per cent. of total ash, 5-5 per cent. of insoluble ash, and 0.4 per cent. of ferric oxide. Soluble cocoa or cocoa essence must not exceed a maximum of 3 per cent. of added alkali (as K,CO,) , and prepared cocoa must contain at least 20 per cent. of fat-free cocoa. Chocolate $ash, coatings, +owder and confectioners’ chocolate shall contain at least 16 per cent. of fat-free cocoa. No cocoa husks, weighting substance, paraffin wax, or foreign fat may be added to cocoa or to any preparation thereof. (49) (50) D. G. H.

ISSN:0003-2654    

DOI:10.1039/AN926510464b

出版商:RSC    

年代:1926

数据来源: RSC