摘要:

216 REMARKS ON SOME POINTS I N WATER ANALYSIS. By A. DUPR~, PH.D., F.12.S. Read before the Yuciety UJ’ Public Analysts, 17th November, 1880. IN the remarks I am about t o make there is, probably, little that is new to shemists frequently engaged in water analysis, and I have been induced to bring them forward chiefly in the interest of our younger members. During the past year I have examined many samples of water which had been purposely polluted by typhoid and other stools, with, or without, the addition of urine. In the course of this work many points connected with water analysis have again strongly impressed themselves on my mind, some of which I will now lay before you. In the f i s t place, 1 would caution analysts, most strongly, against the adoption of bny general standards of purity, such as are laid down by some chemists.We may, of course, find watera of suoh absolute purity that we c m at onw safely pronounce them fit for all216 THE ANALYST. ~ domestic usea, but short ,f this highest purity it is dangerous to rely on any general standards. The only safe standard to go by, in any individual case, is the standard of purity furnished by unpolluted waters of the district from which the sample under examina- tion has come. This, no doubt, is difficult, perhaps impossible, to obtain in every case, but it might be within the power of our Society to furnish such standards for almost every district within the United Kingdom. Referring to the above-mentioned examinations, I may say that I was almost always able to detect, even very minute traces of pollution, if I had a sample of the unpolluted sample water for comparison.The water, chosen for the experiments, however, itself varied so much from week to week that, wit,hout such a direct comparison, even considerable amounts of pollution, comparatively speaking, would have escaped detection by the ordinary analytical methods. Phosphoric Acid.-During the last ten years I have tested every water that has passed through my hands for phosphoric acid, but have recorded the results somewhat roughly only as, none, very minute trace, minute trace, trace, &c., &c., and I am glad to see that this question has been taken up by Hehner and others in a more definite form. The con- clusions I have come to are the following :-The presence of more than traces of phosphoric acid is nearly always a sign of pollution, while the occurrence of much phosphoric acid may be taken as an all but certain sign of sewage or similar pollution, more particularly when taken in conjunction with the standard of the district.On the other hand the absence, or comparative absence, of phosphoric acid cannot be. taken as proving the absence of such pollution, because phosphoric acid may have been abstracted from the water by fifiltration through the soil and by other means; its absence, in such cases, may thus merely prove that the soil through which the water has percolated has not yet been saturated with phosphoric acid, or that other influences causing its removal are present, Permanganate Test.-For many years past I have applied this test to every water analysed, and I have a very high opinion of its value. I know of no test which so certainly distinguishes between unpolluted deep well waters, which often yield analytical results generally indicative of pollution, and even the purest shallow well water.Deep well waters, when really unpolluted, absorb scarcely even a trace of oxygen from permanganate, whereas even the best shallow well waters always absorb a very measurable amount. Were I to be pinned down to the use of a single test I should choose this, and I never report on a water without having applied it. Heisch's Test.-I can speak, I am happy to say, very strongly in favour of this simple test. I have applied it recently t o a number of purposely polluted waters, previously alluded to, as well as to the waters used in their preparation, and I have, in every case, been able to pick out the polluted sample even when the chemical tests had left me in very con- siderable doubt.The only difference in my mode of applying the test, and that first recommended by Mr. Heisch is, I believe, this : he kept his bottles exposed to the light, but at the temperature of the laboratory ; I have kept them at R temperature of between 9SQ and 100" F. I am still continuing my examination of this test, buc meanwhile would most strongly recommend its use to my fellow analysts. Nitric Acid.-One of our leading water analysts, as is well known, entirely neglects this, in my opinion, highly important feature. Whatever may be said, and truly said, as to the innocuous character of nitrates themselves, they are, without a doubt, mainly derived .THE ANALYST. 217 from nitrogenized organic, chiefly animal, matter.In deep well waters, which are above suspicion of pollution from sewage or surface drainage, the presence of nitric acid need not perhaps be taken into consideration ; but the case is widely different when we are dealing with spring, ordinary well, or river water. In all such the presence of notable quantities of nitric acid is a sure sign of previous pollution and as, at present at least, we are not able to differentiate between the various kinds of organic pollution, a water in which sewage, or similar pollution can be proved should always be rejected. In this respect the determina- tion of the nitric acid, taken in conjunction with the standard, in this respect, of the water of the district from which the water under examination has come, is of the highest value, and will often lead us to a correct conclusion as to the character of the water.It must be remembered that the rate of oxidation (nitrification) depends on a variety of conditions and a water which at one time contains much nitric acid and little or no organic matter may, under somewhat altered conditions, contain little nitric acid and much organic matter, even though the degree of pollution has been the same in both cases. Chlorine.-This is one of the few characteristic constituents of sewage which, when once in a water, suffers, as a rule, little or no diminution. The amount of chlorine, therefore, found in a water, when compared with the prevailing standard of the district (not with some fixed standard devised to fit all cases) is one of the very best guides towards the formation of a correct judgment.Alkalies.-I generally content myself with obtaining a rough notion as to the amount of alkali salts present by a comparison of the total hardness of, and the total dry residue yielded by, the water. In most pure potable waters the greater part of the saline consti- tuents consists of lime and magnesia salts, or in other words, the total hardness accounts for most of the saline constituents. In polluted water this is no longer the case, and in these the total hardness often represents but the smaller portion of their saline constituents. Here again the comparison of any special sample with the prevailing type of the district is of great value.In connexion with this, I may be permitted to draw attention to the fact, pointed out some years ago in Germany, that we may sometim'es be able to detect whether the pollution found is due to animal or human urine, by estimating the relative proportions of sodium and potassium present. In human urine sodium is the predominating alkali metal, in the urine of cattle and horses potassium preponderates. Sample Taking.-In taking a sample, from an ordinary shallow well more particularly, it is advisable to have the well pumped for some time, dry if possible, and to take the sample only after tho well has partially refilled. In wells which are not very much used a very great improvement in the quality of the water often tltkes place while it remains in the well, and the analysis of such a sample may lead us to entirely erroneous conclusions.If expense is no consideration it would be well to take two samples of the water, one before, one after the pumping. A material difference between these two samples would, in itself, be strong evidence against the well. Lastly.-I would ask analysts not to assume too readily that even a very bad sample of water is perfectly safe after it has been boiled. It is only necessary to remember that the controversy regarding so-called spontaneous generation, which has now been carried on for many years, is due, entirely, to the extreme difficulty of hilling all living germs in the fluids experimented on.Would any advocate for spontaneous generations be listened to218 THE ANALYST. for one moment if he had simply boiled his solutions in an ordinary tea kettle? I am of course far from affirming that the boiled water is not a3 a rule more safe than the unboiled water, but its absolule safety should not be taken for granted. P.S.-Since reading the above I find that I have omitted to ment,ioe one point I wished to bring forward. The tint produced by the Nessler reagent in the ammonia distillate corresponds, at all events nearly always, with the tint produced in the standard ammonia. This is not, however, the case with the distillate containing the albuminoid ammonia. In this latter the tint produced is occasionally of a decidedly yellower tint than that produced in the standard ammonia, due, perhaps, to the presence of Home compound ammonias.Much to my regret I have not, hitherto, noted this down in my laboratory book, hut shall do so in future. I mention the point because other analysts may have been more careful in this respect than I have been, and if they would give us their experience it is not improbable that we may gain one more valuable guide through the tangled path of water analysis. In reply to Dr. Blyth, Dr. Duprb said he had not tried Wanklyn’s moist combustion process, but he had tried a somewhat similar one, namely, warming the water for some time with an alkaline solution of permanganate and estimating the amount of permanganate remaining, a test which had been in use in Germany for a number of years. He was not, however, so far, entirely satisfied with the test. Chiefly because he found it almost impossible to obtain an alkaline solution of permanganate which, on heating for some time, did not suffer some decomposition. Mr. Heisch, in reply to a question from Mr. Harvey, said he alwajs solutions in as bright a light as he could ; it makes the growth come on He could quite confirm what Dr. Dupr6 had said as to destroying germs. do 80, and he did not find any difficulty in getting his growths almost as water had not been boiled. Considerable discussion then ensued with regard to the suggestion kept his sugar much quicker. Boiling did not easily as if the thrown out by Dr. DuprC as to the practicability of obtaining reliable standards of the various water supplies, and ultimately a committee was appointed to arrange the matter and report thereon.

ISSN:0003-2654    

DOI:10.1039/AN880050215b

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

218 THE ANALYST. ON THE; OCCURRENCE OF TIN I N ARTICLES O F FOOD AND DRINK, AND ON THE PHYSIOLOGICAL ACTION OF TIN COMPOUNDS. By OTTO HEHNER, F.C.S. Read before the Society of Public Analysts, on 17th Xovember, 1880. IN July, 1878 (Chemical News, xxxviii., p. 971,) Mr. A. E. Menke first drew attention to the occurrence of tin in canned goods. He detected and determined the metal in pineapple, apples and in lobster. Mr. Menke’s results have since been confirmed by other chemigts; but as far as I am aware no extended series of analyses has yet been published, with a view to ascertain whether the presence of tin in canned food is exceptional or general. In the case of acid substances, such as fruits, &c., one might fairly expect a notable solvent action upon the metal, but there appeared but little probability of any such action in the case of neutral or alkaline matters, snoh as meats, oils and milk.Mr. Wigner, inTHE ANALYST. 219 his several papers in recent numbers of THE ANALYST, does not mention whether he found the samples, upon which he reported, to be free from tin, whilst Mr. Dyer, in a communica- tion to one of the daily papers, expressly states that he did not detect tin in canned meats. The method of analysis I adopted was as follows :-About 30 grammes of the article to be examined were incinerated in a platinum basin, the ash heated with strong hydrochloric acid, the acid for the most part boiled off; about 30 to 40 C.C. water added, boiled and filtered. This alternate treatment with acid and water was repeated, if necessary, until H,S no longer indicated the presence of tin.The clear and, as a rule, colourless solutions thus obtained were precipitated with H,S, and the precipitate thus obtained, when necessary, further treated in the usual manner. The following vegetable foods all gave abundant yellow precipitates of stannic sulphide :- French asparagus, American asparagus, peas, tomatos, peaches (three different brands), pineapple (two different kinds), white cherries, red cherries, marmalade. In several cases the inner surface of the canister was found much corroded. So considerable is the proportion of dissolved tin in most of the acid fruits, that tin reactions can readily be obtained from two or three grammes of the substances. A metallic taste is sometimes perceptible.The following animal foods were examined :- Corned beef (five different brands), ox cheek, ox tongue (three kinds), collared head, tripe, oysters, sardines in oil, salmon, salmon cutlets, lobster, shrimps, curried fowl (two kinds), boiled rabbit, boiled mutton, roast chicken, roast turkey, ox cheek soup, gravy soup, sausages, condensed milk (three brands). With the exception of the sausages the whole of these samples contained more or less tin. The amount found in one of the soups was 35 milligrammes of tin in one pound canister ; in a tin of condensed milk 8 milligrammes ; in a pound tin of preserved oysters 45 milligrammes, besides a considerable quantity of copper. The metal is to be found throughout the mass of the liquid soups and pasty curries, but resides chiefly on the outer surface of hard meats, such as corned beef.In many cases the canisters were much discoloured and blackened on the inner surface, but in others the surface of the metal was perfectly bright, although there was an abundance of tin in solution. From the results given, it appears, beyond doubt, that tin is most readily acted upon by articles of food, vegetable and animal. Vegetable acids dissolve it abundantly, even if the contact be only of very short duration. Several samples of ginger ale and lemonade, which I have recently tested, gave distinct tin reactions. Even carbonic acid attacks the metal. In aerated waters kept in syphons, the mountings of which consist of pure block tin, the metal is almost invariably found in solution, and on ahaking pure tin filings, or tin foil, with carbonated water, a sufficient amount of tin dissolves in a few days to produce a marked colouration with H,S.The metal dissolves as a stannous compound, and H,S gives a brown colouration. Now, seeing how frequently aerated beverages are reported to be impregnated with lead, and yet how rarely lead enters into the composition of the pipes and cylinders of soda-water machines as now used ; considering further the difficulty of identi- fying lead when present only in traces, I cannot but believe that in many oasea tin has230 THE ANALYBT. been mistaken for lead, Metallic tin readily precipitates lead from its solutions, and even from tin czontaining lead acids do not extract the lead until much of the tin has dissolved, and the proportion of lead in the residue has become considerable.Thus from solder lead can be dissolved simultaneously with the tin. I would advise, therefore, in testing aerated beverages for metallic contamination, to oxydise any stannous salt present, by the addition of a few drops of chlorine water, and after the expulsion of the excess of chlorine to test with H,S. If a black colouration be then obtained, and copper be absent, the presence of lead can safely be declared. It a160 follows, that there is but little danger to be apprehended from the employment of impure tin for the manufacture of tin plates. The tin effectually protects the lead from being dissolved. Seeing then the general occurrence of tin in canned foods, and in articles of drink, the question naturally suggest8 itself,-Is tin, when taken into the system, injurious to health or nat ? The opinions of toxicologists on this point seem to be somewhat divided, and not very pronounced. Most of the works on the subject do not refer to it at all, whilst Taylor dismisses the compounds of tin in his work on 6LPoisons” with half a dozen lines.According to Woodman & Tidy (Forensic Msdicine, p. 229), the chlorides of tin are accredited with being active and irritant poisons. Orfila states that oxide of tin is likewise poisonous, but this assertion has been contradicted by others. Pereira, again, declares that chloride of tin acts topically as an astringent, irritant and caustic, and that when taken as a poison, it causes convulsive movements of the muscles of the extremities and of the face. Some poisoning cases, of old date, are likewise on record, one with fatal result. No doubt the condition of the compounds of tin would, to a great extent, determine whether or not they would prove injurious.Thus tin chloride might be expected to show physiological action, whilst ignited stannic oxyde from its insolubility would prove harmless. The state of oxydation might also modify any action; thus one would conjecture that stannous compounds would be more active than stannic salts. Under the circumstances obtaining in canisters in which food is preserved, stannous compounds in a hydrated and soluble form would predominate. The following experiments may prove interesting, especially since the physiolcgical action of the compounds of tin is but very partially studied :- A half-grown, apparently healthy guinea-pig took with its ordinary food 25 milli- gmmmes of tin in the form of stannous hydrate.This had been freshly precipitated, and had not been dried, but was given shaken up in water. There was no apparent effect. The solid excreta contained much tin after the lapse of a few hours, whilst the metal could not be dstected in the urine. Two days afterwards the animal took 50 milligrammes of tin, as stannous hydrate. After three hours it appeared ill. Next morning it was dead. The quantity of faxes passed since the administration of the second dom was very small, and the size of the faxes had diminished extremely, about to that of those of a mouse. On dissection the stomach was found practically empty, the colon distended with food, the small intestines empty.The liver, kidneys, lungs and heart were separately examined. They all contained traces of tin, the large& quantity being apparently in the It is from the solder that contamination with lead might ensue.THE ANALYST. 221 liver. The main part of the dose given, however, remained in the food contained in the colon, so that comparatively little of the oxyde had been dissolved and absorbed. Death therefore had been produced by a far smaller quantity than that administered, and was apparently due to the astringent and irritant action of the metal. Another somewhat stronger guinea-pig took 30 milligrammes of tin in the form of stnnnic hydrate, also freshly precipitated and moist.As no ill effect seemed produced, another 45 milligrammes was given on the same day. The fseces contained much tin. Next day the animal further took two doses of stannic hydrate of 75 milli- grammes in each. A few hours afterwards it appeared ill; its abdomen was distended, whilst the fEeces were diminishing in size. Next day the pig seemed quit.e well again, and took, without apparent ill effect, three doses of 75 milligrammes each. Thus altogether it had in three days 450 milligrammes of tin, as stannic hydrate, without much injury, although the astringent effect of the tin had become visible. On the day following, when it seemed in perfect health, it took 60 milligrammes of tin in the form of stannous hydrate. It was ill next day, and did not take any food until its death, three days afterwards.The few excrements passed during that time were very small, much like those observed in the case of pig No. 1. They contained much tin. The stomach was practically empty; the colon and bowels filled with semi-fluid green offensive matter, containing much tin. The liver contained a notable quantity of tin, and the lungs, heart, and kidneys, traces of the metal. From these experiments, it appears that whilst stannic hydrate, from its comparative insolubility in gastric juice, is without much effect in the doses given, stannous hydrate, very soluble as it is in dilute acids, is a powerful irritant poison. The spasmodic twitching mentioned by Pereira was quite pronounced in the case of animal 2. I t would be interesting to ascertain whether tin, when given continuously in small doses, accumulates like lead.Canned goods are doubtless but rarely consumed so continuously and in such quantity as to be positively poisonous on account of the tin they contain dissolved, although circum- stances are imaginable, as on board ship or on Arctic expeditions, under which poisonous symptoms might become pronounced. But even the occasional consumption of such goods, containing as they do a poisonous metal in a soluble form, cannot but be more or lsss injurious. Of the mysterious poisoning cases recently repeatedly traced to canned goodg, the tin may possibly have been the cause. Knowing, then, that such articles of food do constantly contain more or less tin, the employment of tin canisters, of tin saucepans, and tin cooking utensils, ought to be much discouraged by Public Analysts and by medical men.The danger may be small, but every item which is inimical to the health of human beings ought to be avoged when once pointed out. On the same principle, we condemn the presence of copper and lead, even in small quantities, in articles of food and drink. The trade in canned goods is one of enormous magnitude, and the subject of the purity of thePe goods is one proportionally important. Surely, human ingenuity will devise means to protect the substance of the canisters from being attacked and corroded by the contents. Such protection bas already been attempted more than once, many of the French preserved vegetables being put up in canisters varnished on the inner surface, The varnish is,222 THE ANALYST.however, burnt away on the seams during the closing of the tins, leaving the solder exposed, and thus not only tin, but lead, is frequently found in the contents of such " protected " goods. Dr. Wynter Blyth said it struck him as possible that Mr. Hehner had rather too readily assumed that the tin in the meat and the vegetables he had examined was in a soluble form, but it was he (Dr. Blgth) thought more likely that very minute particles of tin had been rubbed off by the mere friction of the vsgetable or meat, and therefore if it was of frequent occurrence in tinned meats, they had to deal with the question of whether tin in a metallic state was poisonous. When he was in medical practice he frequently gave aetallic tin in a finely divided state, and he had certainly never seen any bad action follow.He had given at least 350 milligrammes in a finely divided state, and Reen no deleterious action arise from it. With regard to the black precipitant it was well not to be too hasty in putting down that as lead. He had always found considerable difficulty in discriminating between dark discolouration when there was only that to work upon, and that was all there was when there was a mere trace in water. With regard to the symptoms about the excrement being small, it struck him as being on account of the loss of appetite. Dr. Duprk said that in lemonade the lead was traceable to the citric acid used, where, although the action of the lemonade on the vessel in which it was contained was slight, it was nevertheless almost impossible to get citric acid or tartaric acid free from lead. Mr.Dyer said that the letter, to which Mr. Hehner had referred, was written just after an inquest on a child, who had died from eating poisonous tinned meat (or supposed so). Everyone who had tasted it had experienced symptoms of poisoning. The medical man who attended the child did not appear to have made any analysis either of the meat or of the stomach, but he expressed an opinion that the death was due to metallic poisoning, and suggested that it was owing to the hydrochloric acid used in the process of soldering having dissolved some of the tin. Cases of poisoning were by no means confined to tinned meats, many cases happened with untinned- for instance, with sausages.Referring to another point, he wished to ask if any member had had any experience in finding the presence of small quantities of zinc. He had had cases of water being contaminated with small quantities of zinc, evidently derived from galvanic tanks. He wanted to know what quantity was considered dangerous. The point seemed rather obscure. Mr. Wigner said, having had much experience in all kinds of canned goods, he was sure that 20 or 30 milligrammes of tin in the pound could be detected by the taste. He had as yet only found one sample of canned fish which was free from tin present in the fish, This was a tin of prawns, and they had probably been canned less than a month. He did not think that in the case of fish it was merely as Dr. Blyth had suggested, the mechanical adherence of the tin. In nearly every case condensed milks, which had been kept more than a month or six weeks, tin and lead were both present.As to the meats, he had during the late Food Exhibition examined something like 50 different brands of Tongues, Hams, Chicken, Corned Beef, Roast Beef, &c., and there was only one tin (or brand) in which tin was present in any appreoiable quantity; equal to about 0.5 milligrammes in the pound ingtead of the 10 raillilJrctmrnera spoken of by Mr. Hehner. He believed the solder, naed to He had also had another case, of ox tongue.THE ANALYST. fill up the blow holes of the tins, most frequently contained bismuth, and that was at the bottom of the galvanic action which was set up. In the last number of THE ANALYST he referred to a very old can of meat, which was free from tin. With regard to canned fruits he had tried more than 300 varieties, and only about 8 or 10 had turned out bad. He thought an alteration in the character of the tin, or rather of the tinning, would meet the difficulty. Mr. Hehner, in replying, said he did not think there was the slightest doubt that the tin was in a dissolved state, for it was found not only in solid meats but in soups and curries and in compressed meats ; also one could plainly see that it was not metallic tin ; it was not only on the outer surface that the tin was found, but in the parts near the surface as well. He thought Mr. Wigner was very fortunate in getting samples free from tin, as he himself had obtained his indiscriminately, and invariably found tin.

ISSN:0003-2654    

DOI:10.1039/AN8800500218

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

THE ANALYST. 225 ON THE COMMERCIAL ANALYSIS O F CINCHONA BARKS. BY JOHN MUTER, M.A., PH.D., F.C.S. THE immense mass of writing on this subject places the analyst, seeking a good com- mercial process, much in the position of the patient who waE killed by having too many doctors. Having, however, had occasion to study every proposed method from time to time, and being often asked for information, I now take the opportunity of laying before our readers the actual process which I find best in practice, and which I have modified from those originally proposed by De Vrij & Mobs. As to the actual extraction of the crude material I will say nothing, except to state that, of the published processes, the extraction of the bark (previously mixed with milk of lime and dried) by successive portions of methylated spirit of 93 per cent., and then con- verting into sulphates and distilling off the alcohol, is the best, provided the alcohol is only strong enough (which may be cheaply attained by placing a quantity of freshly ignited potassium carbonate in a bottle of the strongest methylated spirit sold) and the bark and spirit are boiled together under an upright condenser.Bark analysts have generally an extraction process, which they keep secret, suitable to the method used by the chief manufacturers for whom they work ; and I do not mean to infer that I, in practice, always 1x88 the extraction mentioned, but I say it is the best published process. Suppose, therefore, that the bark has been cxtracted and the alkaloids obtained aa sulphates in solution, I begin by the very old method of adding to a very concentrated solution-a distinct excess of sodium hydrate, and shaking out with 50 C.C.of chloroform, and then successively with three quantities of 25 C.C. each. This I find will bring back invariably 5-99 out of 6 grammes of pure mixed alkaloids, and is decidedly the most accurate method, given practice in the way of shaking, &c., so as to get the chloroform to settle quickly. The chloroform should be received into a small tared 5-ounce squat beaker, placed under a Wynter Blyth’s recovery apparatus, and the residue dried in the bath at 2120, and then heated in the air bath to 240° F., and the fused mass weighed. The total alkaloids are then dissolved in absolute alcohol, and the solution divided into two equal portions by weight, and treated as follows :- Portiort A is placed under a burette containing volumetric snlphuric acid (11.6 p~.acid of 1843 sp. gr. in 1 litre of water each C.C. of which-*l gramme crystallized sulphate224 THE ANALYST. of quinine) and titrated until just faintly acid to delicate litmus paper, and the acid used is noted as a guide for future operations. The spirit is then evaporated off, and the residue is dissolved in water at 1 8 5 O F., using 5 C.C. of water for each C.C. of volumetric acid taken, and if not all soluble, then volumetric acid is to be dropped in until all is dissolved. The whole being still kept at 185O, very dilute sodium hydrate (4.74 NaHO per litre) is to be cautiously added, stirring well until the whole is just all but neutral.The amount of volumetric acid used to dissolve over that required at first to titrate, will be an index of the soda required, because the solutions are to be made to balance each other. The whole is now rapidly cooled to 60°, and kept at that point for an hour, and then filtered through a pair of filters previously mutually counterbalanced, and the filtrate received into a graduated C.C. measure. The crystals are washed with 1.5 C.C. of water at 60° for each C.C. of acid used in the titration, and when drained, well pressed, and dried first at 2 1 2 O , and then gradually up to 2400 and weighed, using the outer filter as a tare. The filtrate and washings are measured and *000817 added to the weight of crystals of QUININE SULPHATE for each C.C.of the fluid. If the last drops of water running from the crystals are still acid, then the funnel must be placed over an empty beaker, and the washing continued with saturated solution of quinine sulphate at 600 F. till all free acid is washed away, as if not the crystals will char in drying. Portion B is rendered just acid with hydrochloric acid, the spirit evaporated off, and the residue dissolved in the least possible quantity of water at looo F. Dilute soda is added to nentralization, and then excess of saturated solution of Rochelle salt, and the whole cooled to 60° for an hoar with frequent stirring. The precipitate is collected on a pair of mutually counterbalanced filters, washed with say 100 C.C. of water at GOo, and the filtrate and washingg received into a measure.The precipitate is dried at 220° and weighed, using the outer filter as a tare, and -00083 is added for each C.C. of filtrate. The quinine sulphate previously found is multiplied by ,915, and the answer is deducted from the weight of the mixed tartrates, and the balance multiplied by ,804 gives CINCHONIDINE. The filtrate from the tartrate is concentrated to its original volume, cooled, rendered just faintly acid by a drop of dilute acetic acid, and excess of saturated solution of potassium iodide is added with constant stirring. After an hour or so at 60” it is collected like the cinchonidine, and treated in every respect the same, and weighed, and the weight having had -00077 added for each C.C. of filtrate and washings, is multiplied by 07168, and result is QUINIDINE.The filtrate from the quinidine is made distinctly alkaline by sodium hydrate, and the precipitated cinchonine and amorphous alkaloid are filtered out in a similar manner, washed and weighed. The precipitate is then treated with spirit of 40 perAcent. to dissolve out the amorphous alkaloid and again weighed, and the difference is AMORPHOUS ALKALOID, while the last weighing is CINCHONINE. This is the worst separation in the whole process, but as cinchonine is the least valuable alkaloid it is not of any great consequence. The weight of the cinchonine and amorphous alkaloid together must have deducted from it *00052 for each C.C. of the filtrate from the quinidine hydriodide, and *00066 for each C.C. of filtrate rom the cinchonidine tartrate, and the balance is then the true weight, which, minus the amorphous alkaloid, gives the cinchonine.The process is very expeditious, both portions going on at once, and the whole can beTHE ANALYST. 225 done in six hours. Of course, like all others, it requires cxpcrieuco, especially to see that the neutralizations are carried to the exact point, and the quantities of water properly judged, but, given that, I have frequently got back with it 99 per cent. of mixed pure alkaloids, and for Indian Barks it works very well indeed. There is nothing special in the actual separations, but only in the general manner of working, and the saving of time by using the two solutions, and in the collection on double filters so as to compensate the amount of solution absorbed in every case, and in the allowances which are not exactly perhaps theoretical, but what I have practically found the best. No allowance is mentioned for the solubility of cinchonine because it is very slight and not important. The allowance on the first step of B is a practical one based upon a usual sort of mixture of quinine and cinchonidine, but is to be modified according to the quinine found in part A . In practice, however, it is usually close enough.

ISSN:0003-2654    

DOI:10.1039/AN8800500223

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

THE ANALYST. 225 SUBSTITUTE FOR ALUM I N MAKING BREAD. BY J. NAPIER, F.C.S. I BEAD with great interest the article by Mr. C. Estcourt, on the above subject, in the October number of THE ANALYST. Having since then obtained a sample of the liquid from Manchester, I am able to give some further information about it. The liquid is called ‘( yeast improver,” and is recommended to be used in the proportion of eight ounces per sack of flour (280 lbs.). I t is manifest that this solution is not intended as a substitute for yeast, but merely as an adjunct in the case of new flours, and many English flours, where the binding qualities-so essential to making a good, easily -digested loaf-are somewhat lacking. Indeed, with some home flours it is almost impossible to get a satisfactory result.I found the liquid to contain the ingredients, and in simiIar quantities, as Mr. Estcourt stated: phosphates of lime and magnesia, held in solution by phosporic acid. Having certain misgivings as to the purity of the materials used in manufacture, I tested for arsenic and other metallic poisons, but these were completely absent ; so also were free sulphuric and hydrochloric acids. Using eight ounces per sack of flour-making 100 loaves,-thirty-five grains of the liquid will be found in every 4-lb. loaf. The free phosphoric acid in this quantity will not neutralise more than one-tenth the amount of earthy and alkaline phosphates naturally present. The percentage of alumina cannot be any objection to the use of the liquid, there being only *021 grain-equal to -13 grain alum-introduced into each 4-lb. leaf- From the absence of impurities, it is very evident this liquid must be made from very pure materials. This is in striking contrast to the results of analysis of the sampla reported to the Salford bench by Mr. J. C. Bell as being made from phosphates of alumina, lime, and magnesia. I think it only remains for our chemical authorities to say whether or not this liquid, in the small quantities used, is injurious to health; but I think there can be little doubt that their decision will be in its favour. The use of bread containing this solution will be decidedly beneficial in the case of children, where a plentiful supply of earthy phosphates is requisite. Alumina was present to the extent of -06 per cent.

ISSN:0003-2654    

DOI:10.1039/AN8800500225

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

THE ANALYST. LAW REPORTS. _ L _ _ - - __ ______ 226 ____- - What i s Fair Notice to the Public that Milk Sold i s Skimmed :- At Worship Street, William Brainwood, a milk seller, of 480, Old Ford Road, Bow, was summoned for selling milk adulterated with 25 per cent. of water. Mr. B. J. Abbott defended. The evidence of William Walter Burrows, sanitary inspector of Bethnal Green, proved that on August 24th he purchased a pint of milkfrom the defendant in the street. Thedefendant vended his milkin the thoroughfares, going about with a van and large cans of milk. In reply to Mr. Abbott, the witness said he saw a printed card in the van stating that the milk was “ country skim’d milk, sold as adulterated milk,” at 2d. a quart ; but he did not see it until after he had stated the purpose for which he had bought the milk.The defendant then told him that it was sold as adulterated. Witness did not believe that the card could be seen, because the defendant went from door to door serving the milk from a can he carried, and the van was in the road. Mr. Abbott relied on the notice, but the magistrate considered that under the circumstances it was no notice to the public. A certificate of Dr. Tidy, analyst for the parish, was put in, showing that an addition of water to the extent of 25 per cent. had been made, besides the abstraction of cream. Mr. Abbott then said that the defendant denied the addition of water, and asked for an adjournment to enable the defendant to have the sample left by the inspector analysed. The magistrate refused to allow any adjournment, and said he was satisfied, in the absence of any defence, with the evidence.Mr. Burrows added that the defendant had before been fined $5. The magistrates now fined him SlO with 2s. costs, or six weeks’ imprisonment. Objection that Somple iaot Personally Analysed by Public Analyst overruled :- At the Hull Police Court, John Stephenson, cow-keeper, of Thearne, was summoned before Mr. E. C. Twiss, Stipendiary Magistrate, for selling, to the prejudice of the purchaser, a quantity of milk which wits not of the nature, substance, and quality of the article demanded by such purchaser. The prosecution was instituted by the Urban Sanitary Authority of the Corporation and Mr. G. P. Spink appeared in support of thc information, Mr. Dale, Sanitary Inspector of the Hull Corporation, stated that on the morning of the 14th September, he saw defendant snpplying customers with milk, and witness procured from him a pint of new milk, for which he paid 2d.He informed the defendant that he had purchased it for the purpose of being analysed by the Borough Analyst, to whom one-third of the pint was subsequently forwarded. Another portion was given to defendant, and the third part witness retained. Witness put in the analyst’s certificate, which certified that the milk contained 25 per cent. of water. Mr. Laverack: He told you he had no milk to spare, I believe ? Witness : Yes. Mr. Laverack : You got about the last he had ? Witness : Yes ; there was a little left. William Fox, assistant to the Borough Analyst, deposed that on the date named Mr.Dale brought them a quantity of milk which he had purchased from the defendant. Witness made the analysis. Mr, Baynes was present when it was made, and superintended it. They found only 6.25 of solids, not fat, and the results gave 25 per cent. of water. Mr. Twiss : According to your analysis I make it 31 per cent. of water. The whole analysis was in favour of the milk. After cross-examining the witness as to the quantities contained in the analysis, Mr. Laverack submitted that the Act of Parliament was not complied with, first of all because the milk was not personally analysed by the “ Public ” Analyst. He said it was to be analysed by the “ Borough ” Analyst. The directions contained in the Act must be strictly complied with. Mr. Dale said that he mentioned Public and Borough Analyst to the defendant.Mr. Laverack considered it hardly fair to his client that this should be stated after he had raised his objection. Mr. Spink said he took it that Borough Analyst meant Public Analyst. In reference to the first objection, Mr. Twiss said that his impression was that if the Public Analyst were present from the commencement of the analysis to its fulfilment, and if he had somebody acting under his mpervision the objection could not be sustained. Mr. Laverack said that being the case he would beg leave to call the defendant before his Worship decided the second point. The defendant was then sworn. He stated that on the morning of the 14th inst. his milk was sold out before had served all his customers, and he therefore purchased two gallons of milk from a milkseller named George Smith, for which he paid l$d. a pint.He had disposed of nearly the whole of his extra supply when the inspector came up and purchased a pint of it. Mr. Twiss: If that is the case Smith ought to be in defendant’s place. Mr. Spink (to defendant) : Did you never water your milk ? Wltness : No. Mr. Spink : Is it the custom of the trade to water it ? Witness : Yes, a little sup. His Worship said that defendant and others oould not be allowed to sleU milk Mr. Laverack represented the defendant. Witness: Yes, it is 31 as matter of fact. I t was not of tho nature, substance, and quality of new milk. He (defendant) bought the milk in belief that it was as good as his own.THE ANALYST.227 which mas adulterated in this manner. If they purchased an extra supply they must know its quality, for the public must be protected. With regard to the second point raised by Mr. Laverack, he must believe the inspector’s statement and overrule the objection. Defendant would be fined 20s. and costs. Milk Adulterated through it Raining while Milking going on :- Francis Mallisan, cowkeeper, of Hull, was summoned for a similar offence. In this case the analysis was also made by Mr. Fox, Mr. Baynes’s assistant, and the certificate showed that the milk was adulterated with ten per cent. of water. In reply to his Worship Mr. Fox said a cow in the very weakest condition would give nine per cent of solids. This was their standard. I n this the analysis showed only eight per cent.which gave adulteration to the extent of ten per cent. Defendant’s excuse was that whilst milking the cows in the field on the morning of the 14th ult. it rained very heavily, and he thought about a pint of water fell into each of the milking buckets. That was all the water in the milk that he was aware of. He was not in the habit of watering his milk, not even to the extent of a table-spoonful. Many persons said his old milk was as good as new. His Worship said the evidence showed that the milk was adulterated. If it had been adulterated in the way defendant described he must be more care- ful in the future. Fined 20s. and costs. Defendant : May I ask if you are allowed to put any water in then ? His Worship : No, certainly not. Fine French Cofee containing 90 per cent.of Chicory :- At the Bilston Police Court, before Mr. Boughey, the stipendiary for the South Staffordshire district, Mr. Richard Pinfield, grocer, of Ettingshall, was summoned by Mr. Horder, the inspector under the Food and Drugs Act, for selling coffee “ not of the nature and substance demanded by the purchaser.” Samuel Toy, assistant inspector, stated that on July 23 he went to defendant’s shop, and purchased a quarter of a pound of coffee. The coffee was in a canister, labelled “ Fine French Coffee,” and on the label was a statement to the effect that it was a blend of fine East India and other coffees, carefully prepared by the new French process, whereby the aroma and properties of the coffee were carefully developed. The contents of the canister were analysed by Mr.E. W. T. Jones, the official analyst, who certified that the mixture contained 90 per cent. of chicory. The stipendiary said the mixture was not coffee ; it was merely “ stuff,” and he could call it nothing else. As, however, the costs would be something heavy, he would in this instance only inflict the nominal fine of 5s. and the costs, $1 10s.-At the same Court, Mr. Isaac Boyard, grocer, of New Village, near Wolverhampton, was also charged by Mr. Horder with selling adulterated coffee. Samuel Toy, assissant inspector, said he went to the defendant’s shop on July 23, and asked for two ounces of coffee. The coffee was given to him wrapped in a paper, on which were printed the words “ Chicory and Coffee.” The coffee was given to Mr.Jones, the analyst, who found that it contained 73 per cent. of chicory. Defendant was fined lOs., and 51 9s. 6d. costs.-Mr. William Phillips, grocer, of New Village, Bilston, was also summoned by Mr. Horder, the inspector under the Food and Drugs Act, for selling mustard not of the nature and quality demanded by the purchaser. Samuel Toy, assistant inspector, said he went to the defendant’s shop on July 23, and purchased two ounces of mustard. The mustard was sent to Mr. Jones, the analyst, who found that i t contained 49 per cent. of wheat flour. Defendant was fined 5s. and costs, amounting in the whole to 31 10s. 6d. London Mustard containing Wheaten Flour :- At the instance of the Glasgou Sanitary Department, A. M‘Lean, provision merchant, 296, South Wellington Street, in that city, was charged before Sheriff Balfour with having sold adulterated mustard.On October 14 Robert Inglis, one of the sanitary officers, purchased a quarter of a pound of mustard in Mr. M‘Lean’s shop, and on being analysed by Dr. Wallace the mustard was found to contain 25 per cent. of wheaten flour. It appeared that the mustard had been sold by a girl, in the absence of the ordinary shopkeeper, and had been taken loose from a canister on which was printed a statement to the effect that the mustard was “ London mustard,” and a mixture of farina and choice condiments. This intimation was hardly noticeable to purchasers, and the girl did not intimate to the inspector that the mustard was a mixture. In the circumstances, the Sheriff held that while an offence had technically been committed against the Act, it was not a serious offence, and he would only fine Mr.M‘Leaa in the expenses of the prowcution-25s. At the Rushall Police Court lately, before Messrs. F. James, S. Stokes, and T. A. Negas, a number of grocer8 were summoned for an alleged violation of the Adulteration of Food and Drugs Act. The first case was that of Mrs. Caroline James, who was summoned by Mr. J. G. Horder, the county inspector, for supplying goods not of the nature and substance demanded by the purchaser. Mr. Williams (of the firm of Duignan and 00.) appeared for the defendant. Mr. Horder said that on October 9 he went to defendant’s shop and purchased two ounces of coffee. The sample, on being analysed by the county rtndyst, was found to contain 50 per cent.of chicory. In cross-examination the witness said the mixture228 THE ANALYST. was wrapped in a paper on which was printed ‘‘ This is a mixture of chicory and coffee.” The Bench con- sidered the notification on the wrapper to be quite sufficient intimation to the purchaser that it was not pure coffeo, and dismissed the case.-Mr. George Cresswell, grocer, of Walsall Wood, was charged with a similar offence. Mr. Eagnall (of the firm of Rowlands and Bagnall, Birmingham), instructed by the Birmingham and Midland Counties Grocers’ Protection and Benevolent Association, appeared for the defendant. In this case Mr. Horder said the mixture contained 51 per cent. of chicory. The other facts were similar to thow given in the preceding case, and the magistrates dismissed the case.-Sarah Stevens, of Wnlsall Wood, for selling coffee containing 63 per cent.of chicory, and William Bates, of Rushall, for having sold a mixture containing 69 per cent. of chicory, were also charged with a like offence. As the facts were at all fours with the previous cases, the summonses were dismissed.-Thomas Henry Whitehouse, of Shefield, was summoned for having sold as half a pound of butter a mixture containing 92 per cent. of foreign fat. The witness for the prosecution said defendant stated at the time of the purchase that he had bought it for butter. Defendant was fined Sl, and Sl 8s. 6d. costs. Cofee Adulteration.-Extraordinary Defence :- Mr. Charles Isaac Walton, tea dealer, 233, Hoxton Street, was summoned at Worship Street Police Court by the inspector for the Vestry of St.Leonard, Shoreditch, for selling coffee as pure which was adulterated. Mr. Walker, Vestry Clerk, appeared for the prosecution, and Mr. Wontner for the defence. Evidence was given that three-quarters of a pound of coffee was purchased and was asked for as genuine. I t was laid on the counter on an open paper and then was divided into three parcels and put in paper bags and sealed. One was left with the vendor, one was sent to the analyst, and one retained by the inspector. The certificate of Dr. Stevenson was put in, certifying that the sample contained the foreign ingredients as under: Chicory, 20 per cent. Mr. Wontner, for the defence, said he had a strange answer. They had sent the samplcs left to Dr.Hassall for analysis and he certified that the quantity of chicory was 30 pcr cent. But they believed that it was genuine coffee. They had a parcel of pure coffee which they sold from, and they could only account for it by the supposition that chicory was in the bags when the coffee was put in. He should have to ask thc inspector if the bags were clean and empty. The inspector was recalled and said the bags were new from the stationer’s and had never been opened and were quite empty. Mr. Wontner then said they could not account for it as they believed the coffee sold was pure. He asked that the sample produced in Court should be submitted to the Government analyst a t Somerset House. The magistrate consented, and the case was adjourned. At the adjourned hearing the certificate from Somerset House was put in, stating that it contained not less than 20 per cent.of chicory. Mr. Wontner called the proprietor and his employBes to prove that the coffee was sent from the Mincing Lane establishment to this and sereral other places. They sent EL canister to each of pure, labelled as such, and it was sold as such in the full belief that it was pure. The magistrate said there were some peculiar circumstauces about the case which it was not for him to decide. It was admitted that chicory was largely used for mixing with coffee in this place ; whether this was a mistake or not he could not say, but the evidence put before him was not sufficient to induce him to impose a less penalty than $5 and $1 2s. 6d. costs. Mr. Walker said that was a very improper statement.Extensive Adulteration in Scotland.-Heavy Penalty :- I n Chambers lately, before Sheriff Balfour, Alexandra Young, milk dealer, and residing with his father, William Young, farmer, Waterbank, Carmunnock, was charged at the instance of the sanitary authorities with having, on 18th October, from a cart in West Bothwell Street, sold to William T. Armstrong, one of the sanitary inspectors, four pennyworth of cream diluted with 62& per cent. of skim milk, two pennyworth of sweet milk diluted with 36 per cent. of skim milk, and one pennyworth of skim milk diluted with 20 per cent. of added water. In answer to the Sheriff, Mr. Young said he was guilty, and that he was 22 years of age. Mr. Ross, who acted for the prosecution, said this was one of the worst citses that had ever come before the Court, and the locality in which the milk was sold was a poor one, inhabited chiefly by working people.The Sheriff said it was a very serious offence. The adulteration was very great ; it was the worst case that had come before him. The percentage of adulteration usually varied from five to twenty, but in the cream in this case there was more skim milk than cream, the adulteration being 624 per cent. The accused : Well, it was the price I had to pay for it. The Sheriff (continuing) said that in whatever locality these sales had taken place the offence would be great, but it was worse being in a locslity like Bothwell Street, where the people .were poor. I t would have been competent for him to inflict a penalty of S20 for each of the offences, but hc thought it would be too hard to impose three times $20.He would treat the case as if there was only one offence, and impose a fine of $18, which was just $6 for each offence. This modifi- cation was made because of the youth and inexperience of the acciisecl, and he hoped it would be aTHE ANALYST. 229 warning to him for the future. Mr. Ross : Will your Lordship impme a substantial alternative in ccase of the accused not paying this large sum ? The Sheriff : Have you any prospect of paying this penalty ? The accused (who had a roll of notes in his hand) said he conld pay it now, which he did. Milkman Fined for Adding Water t o liL Employer‘s 24allc. James Haines, in the employ of Morgan Morgan, purveyor of milk, carrying on business at 68, Alscot Road, Bermondsey, was summoned to Southwark Police Court by AIr.H. Thomas, sanitary inspector, in the service of the Bermondsey Vestry, for selling him milk containing 16 per cent. of added water, and BIr. Morgan, the master, was charged with causing him to sell it. BZr. Harrison, vestry clerk, prosecuted, and Mr. Washington appeared for the latter. Mr. Thomas said that on the 14th ult. he caused a pint of milk to be purchased from Haines as he was serving customers in Grange Road. He told him he intended to have it analysed, when Haines said he sold it as he received it from his master. Witness took a sample to Dr. Muter, whose certificate showed that it contained 16 per cent. of added water. On mentioning the circumstances to Mr.Morgan, he said that Haines must have added water to it after he left the dairy, as all the milk was tested before it was taken away. Mr. Washington, on the part of Mr. Morgan, produced a certificate showing that all the milk was genuine when Haines took it fiom the dairy. Mr. Thomas \ms recalled by Nr. Washington, and he said that on Haines being called by his master in reference to the milk, he said, ‘‘ I own puttiiig water in the milk ; I have done it three times.” He had known Morgan for some time, and he believed him to be a veiy respectable tradesman. The defendant Haines here said it was quite true what Xr. Thomas had said. He had frequently put water in the milk, and his master knew nothing about it. JIr. Washington informed his worship that Morgan paid Haines 26s. a week, and gave him what milk he required for his own use. I t was very serious for Mr. Morgan. The magistrate dismissed the summons against Morgan, and fined Haines S5, or one monlh’s imprison- ment. For some years past large quantities of butterine have been disposed of in Dublin as pure butter. Hitherto the fraud has escaped almost unnoticed, to the great loss of dairy farmers. Recently, however, the authorities, aroused to action by the Rev. Canon Bagot and other members of the Agricultural Society, have set their faces against the practice. Several of the vendors of this stuff were brought before the police magistrates by the Corporation and sanitary officials lately, and fined in sums of 25 and 210. The certificate of Dr. Cameron, city analyst, set forth that the samples submitted to him consisted of a com- pound of foreign fats, instead of butter fats. I n one of the cases the prosecutiug official deposed that one of the cools of butter was marked butterine, but over the ‘‘ ine ” was placed a similar label marked 10d., so that the apparent marking on the cool was ‘‘ buttcr 10d.” The magistrate said this was a very bad case of deception, and imposed a fine of 210.

ISSN:0003-2654    

DOI:10.1039/AN8800500226

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

THE ANALYST. 229 NOTES OF THE MONTH. The Irish are credited with having a method quite their own of dealing with matters; but if the statement of a Dublin dairyman is to be believed, an inspector who took some milk from him, which proved on analysis to be adulterated, actually called on him before issuing the summons, and said, “ What day was it that I took that milk from you ? because I have forgotten the date.” The milkman obligingly answered, ‘‘ Och, sure ! and wasn’t it on [such a day] ! ” And then, after that, the inspector had him fined ! The Scotch, always ‘‘ canny ” in money matters, have also had their natural instincts exemplified lately. It seems that at a meeting to discuss the necessity of appointing an analyst, a saving ratepayer delivered himself of the following brilliant idea : ‘( I don’t see much use in gettin’ an analyst.There’s the pollis (policemen), they hRe but little to do in the mornin’; they micht analeeze the milk, ye ken ! ” Another case has been settled, which will be found in our police reports, in which the magistrate has decided against a mixture of 90 per cent. chicory and 10 per cent. coffee, sold in a canister labelled ‘‘ fine French coffee,” and having a statement to the effect that it was a blend of fine East India and other coffees, carefully prepared by a new French230 THE ANALYST. process whereby the aroma and properties of the coffee were carefully developed. There being a large quantity of similar articles about in all the shop windows, we should suggest that it would be a useful amendment t o the label to leave out the word “ developed,” and insert instead “modified by an admixture of a blend of the finest and moat carefully prepared roots of chicoriurn.” That would sound very nicely, and might save convictions ; while such a description would almost be more eloquent than that found on a tin of mustard with flour and turmeric, met with in the Glasgow police reports, stating it to be ‘( London mustard,” and a ‘‘ mixture of farina and choice condiments.” After this we shall have the milkmen selling “ the natural milk of the choicest and most beautiful Alderney and other cows, prepared by a process whereby its nutritive qualities are specially dealt with; and i t is rendered more easy of digestion by infants through careful admixture with a well-known agent supplied bx a beneficent Providence-namely, hydric oxide ! ” RECENT CHEMICAL PATENTS.The following specifications have been recently published, and can be obtained from the Great Seal Office, Cursitor Street, Chancery Lane, London. 1880 Name of Patentee. Title of Patent. Price. No. ‘305 J. C. Loeffler . . . . . . Covering Wire with Insulating Material . . . . . . 2d. 1295 E. 1%. Allen . . . . . . Insulating Electrical Conductors . . . . . . . . 6d. 1304 W. B. Lake . . . . . . Utilization of Bamboo Reed for Manufacture of Fibrous Materials . . . . . . . . . . . . . . 6d. 1310 W. C. Young . . . . . . Manufacture of Sulphate of Ammonia . . . . . . 4d. 1324 T. Croysdale . . . . . . Artificial Manure . . . . . . . . . . . . 4d. 1928 W. li. Lake . .. . . . Telegraphic and Telephonic Apparatus . . . . . . 1s. 1329 W. R. Lake .. .. .. Eliminating Phosphorus from Iron in Bessemer Con- verters .. .. .. .. .. .. .. 4d. 1354 C. D. Abel . I . . . . Caloric Apparatus . . . . . . . . . . . . 6d. 1414 C. D. Abel ,. .. .. Caloric Engines .. .. .. .. .. .. 6d. 1365 S. Pitt . . . . . . . . Preserving Alimentary Substances by Cold . . . . 6d. 1385 T. A. Eclison . . . . . . Electric Machines and Motors . . . . . . . . 6d. 1397 C. D. Abel . . . . . . Electric Lamps .. .. .. .. .. .. 6d. 1402 C. D. Abel .. .. .. Filters .. .. . . ,. .. . . .. .. 6d. 1407 0. Heavisicle . . . . . . Electrical Conductors.. .. . . . . . . . . 6d. 1416 P. Jcnzeii . . . . . . l’roduction of Oxygen Nitrogen Gas . . . . .. 6d. 1456 C. JJowe and J.Gill . . . . iklanufacture of Coal Tnr . . . . . . . . . . 4d. 1468 1%. ?;vaiis . . . . . . Preventing the Falsification of Cheques . . . . . . 6d. 1471 A. W. Gillman and S. Spencer. Manufacture and Treatment of Beer . . . . . . 4d. 1478 W. Mann and W. T. Walker . . Purification of Coal Gas . . . . . . . . . . 6d. 1507 (+.And&.. . . . .. Electric Lamps .. .. .. .. .. .. 6d. 1510 G. Wells and A. Gilbert , . Insulators . . . . . . . . . . . . . . 4d. 1611 J. € I . Johnson .. . . . . Telephoiie Switches .. . . .. .. .. .. 6d. 1512 W. A. Hills . . . . . . Production of Tricalcic and Dicalcic Phosphates . . . . 4d. 1536 J. McLaren . . . . . . Manufacture of Sugar.. . . . . . . . . . . 4d. 1546 J. H. Vale . . . . . . Apparatus for Enriching Gas by Admixture of Hydro- Carbon Vnpour .. . . . . . . . . . . 2d. 1352 A. M. Clark . . . . . . Electric Lamps . . . . . . . . .. . . 6d. 1564 G. Davis.. . . . . . . Prevention of Incrustation in Boilers . . . . . . 4d. 163 5 E. P. Alexander , . . . Treating Mineral Hydro-Carburets . . . . . . . . 2d. 1623 J. H. Johnson . . . . . . Tanning or Preserving Hides or Skins . . .. . . 2d. 1649 W. It. Lake . . . . . . Electric Lighting Apparatus . . . . . . . . . . 8d. 1672 S. A. Pet0 . . . . . . Manufacture of Plumbago Crucibles.. .. . . .. 2d. 3228 H. H. Lake .. .. .. Drying Sugar .. .. .. .. .. .. .. 6d. BOOKS, &c., RECEIVED. The Chemist and Druggist; The Rrewers’ Guardian ; The British Medical Journal ; The Medical Press ; The Pharmaceutical Journal ; The Sanitary Record ; The Miller ; Journal of Applied Science ; The Boston Journal of Chemistry ; The Provisioner ; The Practitioner ; New Remedies ; Proceedings of the American Chemical Society ; Le Practicien ; The Inventors’ Record ; New York Public Health ; The Scientific American ; Society of Arts Journal ; Sanitary Engineer of New York ; The Cowkeeper and Dairyman’s Journal ; The Chemists’ Journal.

ISSN:0003-2654    

DOI:10.1039/AN8800500229

出版商:RSC    

年代:1880

数据来源: RSC