摘要:

ON MILK ANALYSIS. BY DR. 9. VIETH, F.C.S., &c. Read bdom the S'ociety of Public Analysts on 15th March, 1882. AT the November meeting of this Sooiety I was requested to bring before the Society my experiences in analysing milk, espeoially thosle obtained in my present position as an analyst to the Aylesbury Dairy Company. I understand perfectly well that it will be of greater importance to you to hear 8ome figures obtained in my laboratory here than those obtained elsewhere, still I think it will not be without interest to you if I tell you in the first place about the method practised and the results of milk analysis arrived at in other places, even in another country-in Germany. There has been a great deal dene in milk analysis in Germany lately, but whilst nearly all the milk analyses carried out and pubIirJhed in England are done by Public54 THE ANALYBT.Analysts for the pizrpose of controlling the milk sold to the public, in Germany the said analyses are done for the greater part with regard to dairying, and only in some few larger places the government think it necessary to have the milk analysed which is brought into the market, Much attention has been paid to dairy farming in all parts of Germany since the last ten or twelve years, arid as the experimental stations for agriculture, of which there is a great number in Germany, have done a great deal of good, it has been thought desirable, even if not necessary, to establish such stations especially for dairy purposes. These dairy experimental stations were established to support practical dairying by scientific researches.The first of those stations is that of Raden in Mecklenburg, established in the year 1876, and presided over by Professor Dr. Fleischmann, together with whom I had the honour to work for four years. There are two other dairy experimental stations at Kiel and at Proskau, under the direction respectively of Dr. Schrodt and Dr. Schmoeger, both very skilful analysts. As all the work done at those dairy stations relates exclusively to scientific experiments and researches, as further those analysts work quite independently, a n d l a s t , not least-as they are thoroughly educated for their work, I have reason to believe that the results of milk analyses published by them are quite correct. The method adopted for analysing milk is the following.To ascertain the water, about 5 grammes of milk are placed in a weighed dish-generally very thin glass dishes are used -containing some sea sand, heated strongly before use, and heated in an air-bath at a temperature of looo to 105O C, until the dish does not lose any more in weight, that is to say, until two weighings do not differ by more than one millegramme. The increase of weight of the dish with sand gives the total solids, the decrease of weight of the dish with sand and milk the amount of water. To ascertain the fat, about 10 grammea are dried up with sea sand, glass powder, or plaster of Paris. The dry powder is put into a case of filter paper covered with cotton wool and extracted in SoxhIet’s extraction apparatus, with quite pure dry ether.After one hour the extraction is generally finished, the ether is then distilled, and the fat remaining dried and weighed. To ascertain casein, albumen and rsugar, about 10 grammes of milk are diluted in a beaker with 200 C.C. of water and acetic acid added to precipitate the casein. Care must be taken to avoid an excess of acid. The casein is collected on a weighed filter, waBhed, dried and weighed. The fiItered fluid is boiled and somewhat concentrated, thug coagulating the albumen, which is collected on a weighed filter. In the filtrate then the milk sugar is ascertained by titration with Fehling’s solution or by polarisation. The nitrogenous matters-casein and albumen-may be asoertainsd by combustion of the solids of a weighed portion of milk with soda-lime, and multiplication of the percentage of nitrogen with 6.25.To ascertain the ash, about 10 grammes of milk are evaporated in a platinum crucible on the steam-bath, the solids are charred, the coal extracted with boiling water, and burnt to ash. The solution of the soluble salts is put back into the crucible, the water evaporated again on the steam-bath and the residue heated very carefully only to dark red-heat. All the quantities of milk taken for analysis are not measured but weighed. A11 the examinations are made in duplicate and the mean taken. The two examinations must not differ more than 0.1 per cent. ; for the ash a still smaller difference is allowed, Having made the analyees in this manner I always came very close to 100 in summing up the yielded percentage of the component prtrte.Uenerdly I found 0.2 to 0.8THE ANALYST. 55 per cent. less, in some cases 0.2 per cent. more than 100. The total solids or the water were, as 1 stated, ascertained by drying at a temperature of 100 to 105O C., that is a temperature at which milk sugar, heated by itself, loses its crystallization water. But the behaviour of milk sugar when heated differs greatly under different circumstances, certainly the changes of its physical properties are not always the same. Dr. Schmoeger, of Proskau, who made a great many investigations regarding this question, wrote to me some months ago--L6 The behaviour of milk sugar does not agree with my experiences in analysing milk. I never found the total solids less than the sum of the component parts." Dr. Schmoeger found that milk sugar loses all its crystaUization water already by evaporating a solution on a briskly boiling water-bath.If the milk solids are heated higher they lose still more in weight. I fouud a loss of from 0.2 to 0.4 per cent. when 1 heated the solids of 5 C.C. of milk for two hours at a temperature of l l O o to 115* C. ; the solids had been obtained by evaporating the milk and keeping it on the steam-bath for three hours and drying in an air- bath of 1 think that this loss is not only owing to the decomposition of the sugar, but also of the fat and protein. Much attention is paid in Germany to the specific gravity, and you will scarcely find any analysis of milk published on which the specific gravity is not mentioned.Now I will give you some results of milk analyses-in the first place those I obtained at Raden. There is a herd of about 120 cows at Baden, and an average sample of the whole morning-and one of the evening-milk is analysed at least once a week. During the year 1879 the limits for specific gravity, total solids and fat were the following :- Specific Gravity., ............ 1.0308 to 1.0325 .............. 1.0311 to 1.0329 Total Solids ................ 11.71 .. 1Zm760/, .............. 11.90 ), 12-84O/, Fat ........................ 2.88 ,, 3.80°/, .............. 2.87 7 7 3*91°/, Specific Gravity. ............. 1.0319 .............. 1,0319 Total Solids ................ 12*18°/0 .............. 12*27O/, Fat ........................ 3*29O/, ..............3.32'1, to looo C. for two hours. MORNINQ MILE. EVENINQ MILE. The average was- For the year 1880 the following figures were obtained- LIMITS- MORNING MILK. EVENINU MILE. Specific Gravity., ............ 1.0304 to 1.0325 .............. 1.0309 to 1-0328 Total Solids ................ 11.21 .. 12*50°/, .............. 11.29 .. 12*72O/, Fat ........................ 2.95 ,, 3-68*/, .............. 2.92 ,, 3'82'1, Specific Gravity.. ............ 1.0315 .............. 5.0316 Total Solids ................ 11.84°/0 .............. 11.93°/0 Fat ........................ 3*26O/, .............. 3.270j0 Average- The figures for solids not fat are in far the most cases between 8.5 and 9.0, they never rise above 9.0, but fall occasionally below 8-5. There were some other researches made at Raden regarding the composition of milk yielded by cows of four different breeda, each of them being represented by four cows.Altogether 124 analyseg wore made for the purpose of those researches. The specific gravity fell only once below 1.029, and rose to 1.0539. The lowest and highest figures for total Bolide were 10.66 and 13.45 per cent., for fat 2.60 and 4.70 per cent. The average of all analyses was for specific gravity 1.0816, for total Aolida 11.78, and for fat 3.23 per cent. The amount of solids not fat varies from 8 to 9 per cent., falls even below $00, and rises in a very few cases above 9.0.56 THE ANALYST. At the dairy experimental station at Kiel ten cows are kept exclusively for the purpose of making experiments. The milk contained in average- In the year 1878... . . . Total Solids 12.43 per cent.. . . . . .Fat 3.70 per cent. ,, 1879,. . . . . ,, 12.13 ,, ,. .. , . ,, 3.42 ,, ,, 1881 ...... ,, 11.93 ,, . . . . . . ,, 3.40 ,, The solids not fat generally fall between 8.5 and 9-0 per cent. At Proskau the milk of a herd of Dutch cows is at the disposal of the dairy institute. The cows are milked three times a day. The average composition of the milk was in the year 1879-Total solids 11.61 per cent., fat 3.19 per cent., the solids not fat fluctuating from 8 to 9 per cent. Looking over all the figures previously mentioned, you will see that the specific gravity does not fluctuate very much, say from 1.029 to 1.034. Regarding the total solids and the fat, we may say that all the milk, with very few exceptions, is to be considered as not at all rich milk.The most striking point, however, will be to you the small amount of solids not fat. The solids not fat are never taken into consideration in Germmy, and therefore 3: had to reckon them out for this paper especially. Now, as I know the value of the figures for solids not fat, I wonder that nobody cares for them there. Two figures account for the amount of solids not fat, namely, those for total solids and for fat. If the former are reduced to the lowest point, the latter raised to the highest, the solids not fat will be found proportionately low. That is the case in the previous analyses, but I repeat that I firmly believe them to be right. Thus much about milk analysis in Germany. It is now about eighteen months since I first came to England, and not quite as long as that since I began my regular work.The Aylesbury Dairy Company thought it necessary to establish on their premises a laboratory fitted up very completely with all instruments and appliances, and to employ an analyst, so that they might be able to extend the system of controlling the milk, as then carried on, to the largest scale, and give their customers the greatest possible security of a regular supply of good, pure milk. Setting aside the two to three hundred examinations by means of the lactDmeter, to take the specific gravity, there are forty to sixty milk sample6 analysed daily to secure the object mentioned. Having this work before me, I had to think of three points-firstly, how to manage it; secondly, how to get the most correct results; and thirdly, how to come as close as postiible to the method of analysing milk generally adopted by Public Analysts. The first thing was, that I had to abstain from weighing the portions taken for analysis.I measure them by means of correct pipettes. Further, I evaporate the milk taken for ascertaining the total solids in platinum dishes without any addition, and lastly, I do not extract the fat in such a way that I have to use the balance, hut ascertain it by means of Marchand’s laotobutyrometer. I perfectly know that I cannot claim €or analyses carried out in this manner the fullest exactitude, but what they lose of correctness on the one side, they certainly gain by their vast number on the other. Regarding the total solids, I carried out a series of experiments to decide whether there is any remarkable difference by evaporating milk with or without sea sand.In all cases I placed 5 C.C. of milk in platinum dishes, and kept the same for three hours on a boiling water-bath, and for two hours in the air-bath at a temperature of 95 to looQ C. When weighed, the platinum dishes containing sea sand generally yielded a little less total solids, but the difference was only a very small one, and never exceeded 0-1 per cent.THE ANALYST. 57 Regarding the fat, of course I had to abstain from extracting it after Soxhlet's method, which I consider the very best and exactest one we have. I had to employ a simple method, taking as little time as possible, and I never was doubtful what method I would have to choose.As I had made testing milk my special study, I always looked out for instruments and methods proposed for this purpose, and found opportunity to examine most of them myself. On the basis of my own experiences, and of those obtained by other analysts, I must say that of all the instruments proposed €or ascertaining fat in milk, Marchand's lactobutyrometer is by far the best one. I expressed that in a book I wrote three years ago, On the Methods of Testirzg Milk, and notwithstanding some new methods having been brought out during the last years, the opinion about the lactobutyrometer has not been changed, as you may see in a book just published entitled Communications of the Board of Health of the German Empire. You will find there the same opinion about the lact obu tyromet er .10 C.C. of milk are measured and pIaced in the tube; 10 C.C. of ether and some few drops of a solution of potassium hydrate are added, the tube then closed and shaken, so that all is well mixed. Then 10 C.C. of alcohol are added, and the closed tube shaken again. After this the tube is placed in water of about 40° C., until all the fat has risen. Then it may be placed in water of about 20° C., and the extension of the fat layer on the top read off. By the aid of a tabIe you will find to how much fat it is equal. The whole operation is finished in about twenty minutes, but even a boy is able to carry out twenty to twenty-five examinations during one hour. When I tried the lnctobutyrometer against Soxhlet's method, I generally found 0.1 to 0.2 per sent.of fat less. I cio not want to harass you with figures, and therefore I only give you some few results of ascertaining fat in milk by the said two methods obtained in my laboratory here. The first figure always refers to Soxhlet's, and the second one to Marchand's method:-3*63 and 3.4, 1.98 and 2-0, 3.16 and 3.0, 3.31 and 3.2, 4.06 and 3.8, 4.23 and 4.0, 3-13 and 3.0, 2.82 and 2.6, 2.90 and 2.8, 2.73 and 2.7, 3.54 and 3-4, 3.73 and 3.4, 3926 and 3.2, 4.30 and 4.2. 1 call those results very satisfactory, and am sure you will arrive so close to the truth as the previous figures tell you; that is to say, you will not find a larger difference against Soxhlet's method, whenever you work the apparatus in the right manner, and use pure washed ether and pure alcohol of the right strength, namely, of 90 to 91 per cent.The strength of the alcohol is of very great importance. I n my laboratory very rnach less satisfactory resuIts were obtained when alcohol was accidentally used which was stronger than expected and forgotten to be diluted. The lactobutyrometer is now very well known in Germany, both in laboratories and in dairies and large milk shops. I by no means think that every analyst ought to buy any new instrument brought out, but I do think one might be allowed to expect some interest in new apparatus, especially when they are brought directly before the eyes of the chemical world. I regret to say that such an interest is not everywhere to be found, otherwise events like the following would be impossible.There was a query in the number of the English Mechanic and World of Science issued January 20th:--"To Mr. Allen or any correspondent. Would you kindly tell me what the lactobutyrometer is that is made by the Aylesbury Dairy Company, and The way to work the lactobutyrometer is a very simple one. It does not seem to be the same in this country.58 THE ANALYST. how it is worked? It seems very complicated in the drawings that they publish with their advertisements. I should have thought the quickest method of getting at the fat was that employed in milk analysis. In the number of the same paper issued February loth, a reply to this query was published as follows:--“I have not seen the advertisement of the Aylesbury Dairy Company referred to by ‘Aconite’ in his query addressed to Mr.Allen or any correspondent, but presume the instrument in question is one for ascertaining the quantity of fat in milk by estimating the extent of the opacity produced by the suspended fat globules. There are many sources of error in such a method, but it would probably give useful results in certain cases, and certainly would be much more rapid than any process based on the extraction of the fat. Signed, A. H. Allen.” I may mention that an advertisement with drawing of the lactobutyrometer wag published on the front page of the December and January numbers of THE ANALYST, the journal of this Society, so that everybody who took THE ANALYST in his hand must have seen it. I want to protest very strongly against mixing up an instrument-which, in my opinion, is of the greatest value for ascertaining the fat in milk in all the cases where it is impossible to make an exact analysis-with the so-called lactoscopes, instruments which are, if of any value-only of a very little one, as the principle on which they are based is wrong.I do not want you to understand that I think the results obtained by using the lactobutyrometer irreversibly right. I myself extract the fat by means of Soxhlet’s apparatus in all the cases of any importance. But I certainly think the lactobutyrometer a very valuable instrument for judging a milk, especially if you have two other figures besides those for the specific gravity and the total solids. At the l a d meeting it was mentioned that there is a possibility to account the specific gravity of a milk by addition of the figures for solids, fat, and water.I suppose that was an error, at least I do not know anything of this kind. Certainly there exist some relations between specific gravity, solids, and fat, and by a series of researches carried out by Dr. Behrend and Dr. Morgen, it seems to be possible to find the amount of total solids of a milk, if the Bpecific gravity and the amount of fat is known, and a table, worked out for that purpose by the said analyste, is used. I n most of the cases I checked this table, I found that it answers very well, and I hope one day I shall find time to go thoroughly into this matter, as I think it quite worth while. If the table is right, I should think it still of greater value to ascertain the specific gravity and the total solids, and account the fat.1 must not omit to state that the lactobutyrometer cannot be used for ascertaining fat in skim milk, as the instrument does not indicate any fat if there is only 1-2 per cent. or less. 1 mentioned previously that there are about forty t o sixty analyses made in my Iabora- tory daily ; a great deal of this work is done by my assistant. Ths way in which the work is carried out has been communicated in what precedes, now I will give you some of the figures obtained. The specific gravity of all the milk samples brought into the laboratory-about 250 daily-was generally found between 1.030 and 1.033; in some few cases it fell down to 1.029, and in some other it rose to 1.034, The average specific gravity of the milk examined during the past year, 1881, was 1.0315.The amount of total solids is in far the most cases 12 to 13 per cent., as lowest figure 11.3, as highest 15.7, was noticed; the Signed, Aconite.” But it is not that what I should like to point out.TfaE ANALYST, 59 yearly average was 12.8 per cent. Fat was generally found to amount 3.0 to 3.5 per cent., the lowest and highest figures being 2.4 and 5.3, the average 3.1 per cent. The last figure, however, is to be considered too low, as there are some wrong figures among them, owing to the use of a too strong alcohol on working the lactobutyrometer. Of course, the figures for solids not fat are affected thereby as well. Generally the amount of solids not fat is between 9 and 10 per cent., the lowest figure noticed was 8.5, the highest 10.6, the average 9-7 per cent.The last figure has to be diminished to the same extent as the average figure for fat is to be raised. I am fully aware that those figures just communicated to you cannot be compared directly with figures obtained by Public Analysts, as the methods of analysing differ. But I should like to put before you the quastion-Are milk analyses carried out in the same manner by all the Public Analysts, or by all the members of this Society, or even by all the members here present? I do not think they are. There are, as far as I know, some differences in ascertaining the total solids regarding time and temperature. There are- and on this point I am quite sure-some differences in extracting the fat.One analyst employs Soxhlet's apparatus, a second one extracts the fat by pouring cold ether over the total solids repeatedly, whilst a third one prefers the extraction with boiling ether. No wonder, when f;he remlts of analysing samples of the same milk by different analysts differ so much, and give a favourable opportunity to daily papers to speak about untrustworthi- ness of chemical science. I saw myself the anaIyses of samples of the same milk made by two Public Analysts, showing the following considerable differences :- Milk-I. Analyst 1. ?, 2. Mi)lk 11. ,, 1. ?? 2. MzkIII. ,? 1. 9, 1, 2. 13*5"/, ; 12*9'/, ; 13.5'1, ; 12*9'/, ; 13.1"/, ; 13*5'J0 ; 4*1°/, ; 3.2'1, ; 3*9O/, ; 3*2°/0 ; 3*2'!, ; 4. 101, ; Solids not fat, 9*4O/,. ,> 9.7"/,* 9 , 9*6O/,.9 7 9 * 701,. 9 s 9 'OO/,. ,, 10*3°J0. Those figures speak for themselves. Two reasons may account for the fact that some Public Analysts deviate from the method of analysing milk adopted by this Society-namely, the bringing out a more convenient or a more correct method. I should object to a certain degree to the first reason, but cannot object to the second one. Thus when you would find that the extraction of fat is more correct by using Soxhlet's method, I should advise you to adopt this method generally, even then, when you would find that the figures for solids not fat would fall occasionally below your present standard. After all, what I have seen in the time since I have been in England, I believe that the milk yielded hare is in general a great deal better than that yielded in the north and middle of Germany.But I also believe that 9 per cent. as standard for solids not fat is too high. To support my assumption, I give you in the following Borne few figures chosen without selection out of a great number of similar ones- Specific Gravity. . . . 1.0305 1.0300 1.0305 1.0300 1.0300 1.0300 Total Solids.. . . . . . . 13*02°/0 12*60°/0 12-44°/o 12-64°/0 12.24°/0 12.38O/, Fat . . . . . . . . . . . . . . 420°/o 3*80"/0 3*60°/, 3+30°/0 3*40'/, 3*60°/, Solids not Fat.. . . . . 8.82°/o 8*80°/, 8*84O/, 8*84'J0 8*84"/, 8*78°/0 In all those samples the solids not fat fftll below 9 per cent., and in average you would say they contain 2 per cent. of added water. I, however, consider them not only as s3amples of quite pure but of a very fair milk.Just in the present month, when, with the winter, hay and elover grow towards an end, and the farmers-ae it is the same here and 1 2 3 4 5 660 THE ANALYST. everywhere-do not like to put their hands into their pockets and spend some money for buying food, you will find a great deal of genuine milk with an amount of solids not fat below 9 per cent. I should propose to take 8 5 per cent. as standard for solids not fat. The standard for fat might be raised to 2.95, so that the smallest amount of total solids demanded would be 11-25 per cent. We all know perfectly well that in some cases it is quite impossible to state that some water had been added to milk. Add 10 per cent. of water to a milk with a specific gravity of 1.033, with 14 per cent.of total solids and 4 per cent. of fat, and you will have a mixture with a specific gravity of 1.030, 12.7 per cent. of total solids, and 3.6 per cent. of fat. By adding 15 per cent. of water the solids not fat would fall below the limit of 9 per cent., they would come down to 8.7 and you would state the milk contains 3 per cent, of added water. I must say that I have always a peculiar impression by reading such a statement. Everybody will know that the profit of an addition of 3 per cent. of water to milk would not cover the risk, and that therefore an adulteration in such an extent will sczrcely be executed. 1 think you could come very easily over this little difficulty if you would not state that so and so much water has been added to the milk, but that the milk falls so and so many per cent. below the standard. By adopting this form for your statements you would be able at the same time to distinguish milk with higher amounts of solids, saying it runs so and EO many per cent. above the standard, and such a statement might be of some value now and then. Before I conclude my paper I ahould like to call your attention to the great importance of taking the specific gravity of milk to be tested. 1 ascertained the specific gravity of thousands and thousands of milk samples, but never1 found it below 1.029 when 1 had a normal and well mixed milk of at least five cows. There are so many milk analyses published in this country without mentioning the specific gravity, which in many cases would give a very good control of analytical figures. Of course, if a lactometer is employed or taking the specific gravity, one has to examine the instrument, whether it shows the right specific gravity. I have had a great number of lactometers in my hand which differed two, three, and even more degrees. The larger the space for one degree on the scale is, the better it is. Those lactometers are very convenient which are combined with a thermometer, so that specific gravity and temperature may be read off at the same time. I should like to touch on yet another question.

ISSN:0003-2654    

DOI:10.1039/AN882070053b

出版商:RSC    

年代:1882

数据来源: RSC

摘要:

60 THE ANALYST. ON SOME POINTS IN MILK ANALYSIS. BY OTTO HEHNER, F.C.S., F.I.C. Read before the Xociety of Pz~blic Analysts o n 15th Mad&, 1882. IT can hardly be expected that anything very novel can be brought forward in a subject which has been so well ventilated, and which before all others has engaged the attention of Public Analysts, as milk analysis. But from some statements which have recently been made before us (see Mr. FV. Johnstone’s paper in No. 72 of THE ANALYST) and elsewhere, it appears that not a few analysts have forgotten, that the results obtained by the analysis of milk are not results laying claim to absolute scientific accuraoy, but are only comparative ones, and that the limits adopted by the Society-9 per cent. of solids not fat and 2.5 perTHE ANALYST.61 cent. of fat-hold good only when each analysis is made in the manner which led to the adoption of these limits; namely, by drying five grammes of the milk for two and a half to three hours over an open water-bath, and by exhausting the residue with from three to six successive quantities of boiling ether. Modifications of this plan have gradually crept in, and concurrently with the adoption of these modifications, instances have multiplied in which undoubtedly genuine milk did fall below the Society's limits. Although it cannot be held that the deficiency in solids not fat was in every case due to the modification in the analytical process, it yet appearg certain that in many instances the cause lay less with the milk than with the analyst, The object of the few experiments laid down in this paper was to ascertain how far the results depended upon the details of the process adopted.I.-TIME AND MANNER OF DRYING. A. 5.2967 grms. of milk were evaporated in a platinum basin, the residue dried on an open water-bath, and weighed every hour. Weight of residue after 2 hours . . . . . . . . . . 3 9, . . . . . . . . . . -5971 11-27' . . . . . . . . . . a5960 11.25 4 7, 5 9, . . . . . . . . . . -6944 11.22 6 1, . . . . . . . . . . -5941 11-21 .6037 or 11.39 per cent. B. 5.0916 grms., treated as above. Weight of residue after 2 hours . . . . . . . . . . 05769 or 11.32 per cent. 3 ? 9 . . . . . . . . . . *5727 11.25 4 9 , . . . . . . . . . . -5714 11.22 5 ,, . . . . . . . . . . -5702 11.19 6 9 ? . . . . . . . . .. .5698 11.19 C. 5.3288 grms. of the same milk were evaporated on a water-bath, and the residue dried in a dosed water oven. Weight of total solids after 2 hours . . . . . . . . . . -6094 or 11.43 per cent. 3 . . . . . . . . . . . . *6033 11.32 4 . . . . . . . . . . . . %006 11.27 5 ,, . . . . . . . . . . -5981 11-32 6 . . . . . . . . . . . . -5972 11.20 7 ,, . . . . . . . . . . 5958 iia D. 5-3354 grms. dried in a water oven, as in C. Weight of total solids after 2 hours . . . . . . . . . . -6209 or 11.63 per cent, 3 . . . . . . . . . . . . ,6091 11.41 4 . . . . . . . . . . . . *6042 11-32 5 . . . . . . . . . . . . ,6015 11-27 6 . . . . . . . . . . . . a6001 11.25 7 . . . . . . . . . . . . -5977 11-20 C and D, weighed after eight hours, showed no further decrease.E. 5.2980 grms. of the same milk, dried in a water oven. Weight of total solids after 2 hours . . . . . . . . . . -6132 or 11.57 per cent, 3 ,, . . . . . . . . . . ,6047 11-41 4 . . . . . . . . . . . . *6015 11.35 5 . . . . . . . . . . . . -5965 11.26 6 . . . . . . . . . . . . -5951 11.23 7 . . . . . . . . . . . . -5925 11.18 8 ,, . . . . . . . . . . -5919 11.1862 THE ANALYST. F. 5.0560 grms. of another milk gave, on drying on the open water-bath- Weight of solids after 3 hours . . . . . . . . . . . . . . . . . . . . a5464 10.80 . . . . . . . . . . *5488 10.75 . . . . . . . . . . -5438 10.75 -5500 or 10-88 per cent. 4 I t 5 !! 6 t t G. 5.2227 grms. of the same milk, treated like F., gave total solids, after 3 hours . . . . . . . . . . 5855 or 10.83 per cent, .. . . . . . . . . 5629 10.78 . . . . . . . . . . -5610 1074 . . . . . . . . . . *5597 10.71 . . . . . . . . . . *559Q 10.70 4 $ 1 5 t I 6 I t 7 9 ? 3 hours . . . . . . . . . . -5818 or 10.88 per cent. 4 I 9 5 I t 6 !> 7 t f 3 horns . . . . . . . . . . ,5667 or 11.01 per cent. 4 t I . . . . . . . . . . -5590 10.86 . . . . . . . . . . 5546 10.77 5 ? I . . . . . . . . . . *5625 10.73 6 9 ) . . . . . . . . . . -5519 10.72 7 9 3 H. 5.3447 grms. of the same milk dried in a water oven. . . . . . . . . . . 5974 10.80 . . . . . . . . . . -5743 10.75 . . . . . . . . . . -5727 10.71 . . . . . . . . . . -5720 10.70 I, 5.1463 grms., treated as H., gave total solids, after It follows from these ggures, that milk residues are not really dry after having been heated for three hours, but continue to loss weight until they have been heated from six to eight hours.The results obtained are aImost absolutely uniform after drying to constancy, but are by no means so satisfactory after three hours only. Thus, while the greatest difference between the really dry solids was in case of milk I., 4 3 per cent. ; and in milk II., 0.05 per cent., the percentages differed after three hours *17 and 918 from each other. The loss on drying from three hours to constant weight-the weight being taken constant when the loss per hour was less than olze milligram-varied from -06 to -29 per cent. It is also seen that milk residues dry somswhat more rapidly on an open mater-bath than in a closed water oven. 11.-TEBIPERATURE OF DRYING. The dry residues from A and B were placed side by side into llOQ c.A. Weight of resid-ie after 1 hous's drying at l l O o 2 I ? I t 3 I ? I t 4 I ! !> 5 ! I t ? 6 17 I ? B. Weight after 1 I ? 7 ) 2 !! 9 3 3 I ? ! t 4 I > t t 5 9 7 $ 9 6 I7 1, F. Weight after 1 I ? I t 2 I t !I 3 ? I t ? 4 9 7 77 .. .. .. .. .. '. .. .. .. .. * . .. .. .. .. .. .. .. .. * . * . .. .. .. .. * . .. .. .. .. .. .. an nir-bath, heated to -5894 or 11.13 per cent. ,5871 11.09 -5834 11.01 -5817 10.98 -5809 10.97 -5783 10.92 -5588 or 10.96 per cent. ,5492 10.79 -5480 10.76 -5465 10.93 -5446 10.70 *5410 10.68 ,5390 or 10.66 per cent. ,5363 10.60 -5347 1057 ,5340 10.56THE ANALYST. 63 A11 residues, heated at llOQ, become highly rancid, and slightly brown. A had diminished 029 per cent., B -51 per cent., and F -19 per cent., by drying at 1100, after constant weight at looo had been obtained.I t is remarkable that A and B, although heated in the same bath together, yet lost weight very unequally. III.--MoDE OF FAT EXTRAUTION. D, The dry residue from D was extracted in a Soxhlet apparatus with absolute ether, and then dried in a water oven to constancy. Weight of solids not fat after 1 hour's extraction . . . . 0.4554 or 8.54 per cent. 2 9' $ 7 . . . . . . 04521 8-47 The weight did not further diminish by a third treatment of one hour. C. The dry residue of C. was boiled out with six successive quantities of ether. Weight of solids not fat E. The residue of E. was digested with ether over-night, and next morning boiled out Weight of solids not fat *4589 or 8-68 per cent.Weight of solids not fat -4535 or 8.56 per cent. . . . . . . . . . . . . -4618 or 8-67 per cent. with six lots of ether. . . . . . . . . . . . . After further treatment with six quantities of boiling ether : Residues A and B (dried at lfOO) were treated in Soxhlet's apparatus for two hours. . . . . . . . . . . . . A,-A gave -4361 grms. or 8.23 per cent. of solids not fat. B.-B ,, .4101 ,, or 8.05 ,, ,Y ' 9 G . The dry solids were boiled out with ether. 3 times. Wcight of solids not fat . . . . . . . . . . -4508 or 5-63 per cent. 6 '> 9 9 ) ' 9 . . . . . . . . . . *4420 8.46 ,? . . . . . . . . . . *4422 846 H. Extracted in Soxhlet. 1 hour. Solids not fat . . . . . . . . . . . . . . -4484 or 8.39 per cent. 2 9 1 i , . . . . . . . . . . . . . .-4469 8-36 I. F. K. The dry solids were treated with ether over-night, then boiled six times with ether. Solids not fat . . . . . . . . . . . . . . *4363 or 8.48 per cent. The solids dried at llOQ were extracted in Soxhlet for two hours. Solids not fat . . . . . . . . . . . . . . -4184 or 8.28 per cent. 12,9100 grms. of milk, which yielded by two hours treatment in a Soxhlet extractor 3.12 per cent. of fat, were evaporated on a water-bath with occasional stirring go as to granulate the residue; this was boiled out with six quantities of ether, and the fat determined direct. The perfectly dry residue from 5 grms. of the milk K. was extracted six times with absolute ether, containing 10 per cent. of absolute alcohol. Fat obtained, 2-98 per cent. From the results of these fat and solids not fat determinations, it follows that boiling out the total solids with three, six, or more successive quantities of ether, yields about 0.2 per cent.less fat than is obtained by two hours' trgatment in a Soxhlet extractor; that 110 more fat is extracted by prolonged action of ether upon the solids than by mere1.y boiling out ; that granulation of the milk residue does not render the latter more amenabIe to the ether treatment ; that 10 per cent. of absolute alcohol in the ether used for extraction but little effects the result; and lastly, that by the drying of the total solids at 1100 the amount of fat is not appreciably affected, but that only the solids not fat are diminished. Obtained 03509 grms. or 2.72 per cent. L.64 THE ANALYST. IV.-ASH DETERMINATION.A weighed quantity of milk I. was evaporated and incinerated at the lowest possible temperature-below visible red heat. Found *68 per cent. ash. Another quantity, incinerated at red heat, yieIded *66 per cent., and a third portion, heated to bright red heat in a large Bunsen flame gave 0.64 per cent. of ash. A sample of milk II., weighing 5.22136 grms., ineinerated at the lowest practicable heat, furnished 0,0342 or 0.65 per cent. of white ash. This, heated in a Bunsen flame with gradually increasing gas pressure, fell to 064, -60, 0.59, and lastly, at bright red heat to -58 per cent. The solids mot fat of the same milk, carefully incinerated, yielded 0~68 and 0.67 per cent. of ash ; and in two further experiments, at red heat 0.65 and 0.62 per cent.I t follows, that identical results are obtained by incineration of the whole milk, and of the solids not fat ; that is to say, that the mineral constituents of milk are quite insoluble in ether. I t also appears that milk should be incinerated nt the lowest possible tem- perature, a sensible proportion of ash being volatile tit red heat. The figures of the few simple experiments recorded above, place beyond doubt that apparently slight deviations from the commonly adopted procedure of milk examination lead to widely discrepant results, am? in every instance do the modifications in the method of analysis which I have examined tend to yield n lower amount of solids not fat, and a larger percentage of fat than does the original (Wanklyn) method. Thus, taking the average of nine observations, milk solids, dried for three hours, diminished by -14 per cent.by drying them at 100° C. to constant weight ; the constant solids further diminish. 0.33 per cent. when heated at l l O o (average of three observations). The same milk will therefore yield after three hours drying 047 per cent, more solids than when dried to constancy at 110*. And further, by other treatment in a Soxhlet extractor from 0.1 to 0.2 per cent. more fat is obtained than by the ordinary boiling out with six successive quantities of ether ; so that altogether the solids not fat ma,y readily be diminished by 0.6 to 0.7 per cent. by thorough drying and extraction, and a milk furnishing by the Wanblyn method 9 per cent. of solids not fat be credited with no more than 8.3 by other methods. That this is a very notable difference will not be gainsaid, and Public Analysts will have to consider most seriously whether the time has not arrived to alter both the official method of analysis and the official limits. It appears to me, that as much more concordant results are obtained when the solids are dried to constant weight than for three hours only, and that as the fat is much more completely, readily, and with a less amount of trouble extracted in an extractor such as Soxhlet's, it would be well to discard the old plan, and accordingly to lower the limit of solids not fat from 9 to 8-5 per cent. The plan then would be to dry about 5 grms. of milk for from 6 to 7 hours at looo ; to extract the dry fiolids for two hours in an extractor with absolute ether, again to dry the solids not fat to consiancy, and then to incinerate them at the lowest possible tem- perature, only one quantity of 5 grms. being used for the whole analysis. Such a procedure should not, however, be adopted without the full consent of all Public Analysts, in order t o insure in a greBter measure than heretofore absolute uniformity in the method and in the results obtained. Drying at llOo is inadmissible and mischievous.

ISSN:0003-2654    

DOI:10.1039/AN8820700060

出版商:RSC    

年代:1882

数据来源: RSC

摘要:

THE ANALYST. 65 ON METAPHENYLENE DIAMIME AS A REAGENT FOR THE DETERMINATION OF NITRITES I N WATER. BY A. PERUY SMITH, F.I.C., F.C.S., Assistant Chemical Master, Rugby School. THE use of metaphenylene diamine was introduced to the notice of the Society of Public Analysts on Feb. 16th 1881, by Mr. Williams [ANALYST VI. 361. Since then I have at various times tried to obtain from wholesale chemists, either the base, or its salts, but with- out success. This failure impressed me with the belief that there was some difficulty in the preparation of metaphenylene diamine, but upon trial I found that such was not the case ; that is to say, it ‘is easy to prepare a reagent that will give an orange colour with NO,. I will not guarantee its purity. The method I have pursued is as fdows : Take of Nordhausen Sulphuric Acid 100 C.C.Strongest Nitric Acid 100 C.C. Nitrobenzene 20 C.C. Place in a flask, agitate, boil, and allow to stand till cold, when pour into much cold water Allow to stand for some time; filter, wash the precipitate first with cold water, and then with cold alcohol, and finally crystallize from hot alcohol, decanting the alcoholic solution from any orange oily liquid that does not readily dissolve. The crystals which separate from the alcohol on cooling, consist chiefly of metadinitro- benzene. They should be of a very pale yellow colour, almost white, and yield M.Ph.D. on redaction by nascent hydrogen. I tried various methods of effecting this object, the most successful being by the use of iron filings and HCl. The flask or beaker may be heated.When reduction is complete, filter, nearly neutralize the now red liquid with KHo solution, leaving a slight amount of free acid ; heat and filter from precipitated FeO. Acidify filtrate with H,SO,, add animal charcoal and filter ; both precipitates may be washed with alcohol. The resulting solution should be coIourIess, or faintly yellow, and may amount to about 400 C.C. 1c.c. will give 8 decided colour with KNO, and H,SO, in the manner recommended68 THE ANALYST. by Mr. Williams. [op. cit.] The actual strength of the solution does not seem to be of very much importance. If economy be studied, the mother liquid from which the MDNB was crystallized may be precipitated by the addition of water, and the resulting crystals reduced, the product will however be coloured.This colour is not of much consequence, as owing to the small qualttity used in testing, the tint is unappreciable. The residue which does not readily dissolve in hot alcohol, will also yield some M.Ph.D. on reduction, but it is not worth while to do so as the solution will be highly coloured and contaminated with aniline, formed by the reduction of residual nitrobenzene. With regard to the manner of employing the reagent, I have nothing to add to the directions already given by Mr. TVihms, except that I find it convenient to evaporate the water I am testing from 500 C.C. to 100 C.C. or less. [NOTE] .--Since writing the above I find, on referring to Hofmann’s original researches on the aromatic diamines [PYOC. Roy. Sue. Vol. XI. 5211 that he prepared phenylene diamine by distilliiig dinitrobenxene with iron and acetic acid. I have not tried this method. Hofmann does not say if he distilled in a current of H. or GO, ; I presume not. Since, however, metaphenyleiie diamine oxidizes with facility, it might be better to do so, or receive the distiIlate in weak acid so as to form a salt at once, and then crystallize.

ISSN:0003-2654    

DOI:10.1039/AN882070065b

出版商:RSC    

年代:1882

数据来源: RSC

摘要:

66 THE ANALYST. A METHOD OF DISCRIMINATING BETWEEN OXYGEN ABSORBED BY NITRITES AND ORGANIC MATTER. By FRANK 9. PERKINS. BEAUTIFUL as the permanganate process, elaborated by Dr. Tidy, undoubtedly is, its use- fulness in relation to water analysis would be much enhanced were it possible to determine and definitely fix by its aid the limits of absorption of oxygen by nitrites and organic matter. The artifice at present employed-viz. : to allow the standardized perrnanganate to act for a few moments, and then place the oxygen consumed in that time to the credit of the nitrites-appears unsatisfactory, for evidently an approximation to the truth can only be arrived at by acting in this way. I t occurred to me that oxygen absorbed by nitrites may be more correctly estimated (in an indirect manner) by altogether destroying them before applying the permanganate. When my last paper was submitted to YOU, I was not aware that the action of magnesium on water was sufficient, in the cold, to decompose it rapidly enough for the purpose there required ; but experiments since performed have assured me of the fact.It is advantageous, however, to favour the reaction by the addition of a small quantity of sodium chloride. Contact with platinum is unnecessary, although, if preferred, increase of power may also be gained in that way. It will be needless to enter into minute pai.ticulars : it is enough to say that the nitrites (and nitrates) having been broken up (and care must be taken by the application of some qualitative test to a portion of the water that this is effectually done) 250 C.C.of the prepared water and 250 C.C. of the water in its original condition are placed in flasks, and 10 C.G. of dilute sulphuric acid, prepared in the usual way, added to each. The flasks are now heated, and the water brought to the boiling point ; the lamp is then removed, and after a short interval 10 C.C. of the atandwrd permanganate run intoTBE ANALYST. 67 either vessel and allowed to act for three hours, the water gradually cooling during the time. The usual manipulations accompanying the titration with hyposulphite are then gone through with, and the experimenta being concluded the difference between the two represents the amount of oxygen consumed by the nitrites contained in the water. EXETER WATER FROM TANK.Per 100,000 pts. oxygen absorbed. 1. The water before being acted on by Mg. 2. The water before being acted on by Mg. . . . . . . . . -101 The water after being acted on by Mg. . . . . -068 -103 The water after being acted on by Mg. . . . . . . . . -081 Differencedue to' Nitrites . . -033 E -028 N. . . . . . . . . Difference due to Nitrites .. .022=*019 N. FROM LABORATORY TAP. 3. The water before being acted on by Mg. The water after being acted on by Mg. Water before being acted on . . . . . . . . . . Water after being acted on . . . . . . . . . . Difference' iue to Nitrites 4. Experiment with Copper-Zino Gouple- . . . . . . . . . . Difference due to Nitrites Per 100,000 pts. oxygen absorbed. . . -0937 . . -0593 . . -0344 =*0301 N. . . *098 . . -0644 . . *0336=*0294 N.SOCIETY OF PUBLIC ANALYSTS.Analyses of English Public Water Supplies i,n March, 1882. All results are expressed in GRAINS PER GALLON. Description of Snmplc OXYGEN, Absoibad in Date when drawn. HARDNESS, Clnik's Scale, New River . . . . East London . . Southwark & Vauxhall . . ] West Middlesex Grand Junction Lambeth .... Chelsea . . . . . . ~ I ,, 14 ,, I) " 25 ,, 22 ,, ,, 25 ,, 15 Birmingham . . Brighton. . . . . . Bolton.. .. .. .. Bristol.. . . . . . . Cambridge .. .. Canterbury.. . . Croydon . . . . . . Dublin.. . . * . . . Mar. 7 grnsh. v. s. tur' ,, 9 pale blue clear ,, 14 1 s.turbid ,, 6 gmsh brown ,, 16 c . p. blue ,, 17 1 p. blue ,, 21 I brgt. coloilrlesf Feb. 28 1 s. yellow s < Phosphoiio 9 2 Acidin M - l'11osphatcs. 1 $2 I Z e .'8 c: 5 g g f l $4 *0053 *002 1 *0025 005 6 90053 -0060 -0049 *0056 5 . d J I ; j @ 5 2 1-81 1.12 1.20 1 31 *98 1-14 1.49 1912 2-66 2.13 .50 -90 1.40 1.47 1.19 *89 -80 .98 1.09 4.80 2.30 1.10 *95 2.60 2.39 -74 -- 2 2 -3 i: -. - -0020 *0007 -0017 none 4007 *0020 -0007 -0028 -0025 none -0020 *0003 a0014 -0050 none *0010 .0008 ,0014 ~0009 -0007 __-- eea. - After ;oiling - 6 9" 4.5O 5*oo 3.50 2.00 3-70 3-50 5-00 in Before 3oiling. 81.40 14*0° 15 0" 15.5" 12-5" 14 2 O 16-00 18.0O 11-59 l a 0" 3 G@ 17.4' 16 00 4.9" 13*0° 1.3" 4-70 2 40 15.6" 11.00 19.2" 19.0" 3.4" 17-00 XG.6" 1.8" --- Appeaiance i n Two-foot Tube. Microscopical Examination of Deposit. AN ALT STS . L hou1 s at 80" F!'aLu.. -024 .010 -082 -052 -062 -094 *049 -084 . .~ 6 i r i i r i h at 800 Pahr. 414 -062 -036 -027 -027 -028 -026 -0% ,022 -008 SO18 SO18 none so03 none *060 ,012 *01s ,006 -002 ,007 -162 -042 ,011 -007 *017 -- _____ trace trace none tiace trace trace trace trace trace none none none trace trace tracc none trace trace trace trace trace trace trace trace none ____II none _________ ~ TVigner & Harland.R. Dyer. Wigner & Harland. J. Xutcr. 0. IIehner. A. Wynter-Blyth. J. Muter. A. Dupri:. ~ none none non c nonc none none none none none none none none none none none none none ii on c! weedy s. peaty none none none p. blue clear clear clear greenish p. y. & clear greenish yelloa p. yellow p. y. & clear c. p. green satipfactory satisfaccoq nycm. vg. db., fib., aninl. satisfactory none satisfactory -061 ,040 -040 -040 -026 -006 -012 el90 -050 -045 -007 -005 -010 -230 *loo -018 *OO!I *076 6 30 3.0" 3.4" 2-90 5-00 4.0" 6 50 -7O 4.4" 2-4" 6%" 6.0" 8.2" 5.50 3.1' 7.6" 7 30 1.7" 20.4 20.6 8.8 19 6 24.5 10.0 24.6 4.3 5.5 7.0 23.9 27.5 31.2 21.2 7.8 37.5 33 0 4 7 A.Hill. Wigner & Harland. W. H. Watsoii. F. W. Stddart. J. West Knights. 8 Harvey. C. Heisch. C. A. Cameron. J. Falconer King. F. 1'. Perhns. A. Ashby. H. F. Cheshire. J. Napier. W. Jolmstone. A. Sinethem. *0031 *0032 a0048 -0028 so050 *0030 -0040 *0010 -0056 .0015 -0014 fibres, veg. debris mineral and veg. deblis sand, algE sat,isf actoi y s. mineral none satisfactory none mid. and veg. diatoms liatoms, mvg orgms., &c. satisfactory satisfdclory reg. debris, diatoms mvg. [orgms. bacteria, &c 4036 4060 -0007 4063 -0014 -002s -63 -62 none I @007 ~ *0007 -0029 ~ 4028 M.A. Rdams. M. A. Adams. ?T. Thoinson. none none s. mineralDescription of Sample. *Newark . . . . Newcastle -on- Tyne.. . . . . Nottingham . . NorwiCh . . . . . . P Q O h . . . . . . . . Portsmouth . . Reading . . . . . . Roohdale.. . . . . Rugby . . . I . . . Salford . . . . . . Shrewsbury .. Bouthampton . . Swansea . . . . . . Whitehaven ,. I Schuylkill . . . , Philadelphia * The Trent was in . turb. p. brwn. 3. turb. f. yell. bluish green f. grnsh. yell. s. turbid G. greenish light green p. yellow turb. c. 1. yellow c. colourless clear c. f. green turb. yellow this sample was ti SOCIETY OF PUBLIC ANALYSTS, Analyses of English Public Water Supplies in JfarcJz, 1882. A11 yesults are expressed in GBAINS PER GALLON. Appearance in Tmo-foot Tube.none none none none none f. weedy none none none none none none none en. 1-19 -94 1.91 1-86 -2.50 1.00 -66 1-03 *90 1.45 -90 9 0 -39 -32 trace trace trace trace trace trace trace none h. trace none none h. trace trace none trace -09 *04 -74 -52 -05 -17 -12 ,009 -38 ncne a 3 3 -19 trace -01 -107 4013 -0010 -0020 trace trace trace *0007 ,003 4056 -0014 -002 5 *0051 -0010 none -0063 - ! z G .E! g 0 .- 0 $4 ,0084 -0090 ,0124 -0060 -0032 ,0042 *0056 004 *0280 -0028 -0030 -0087 -0056 *0008 -0084 OXYGEN, Absorbed m ' mins ,t 800 Fahr. -046 *060 -018 -054 -039 none *033 *0007 -035 -003 -004 -015 -003 *006 I_ - hours It 800 Fahr. -- -099 -107 *026 ,094 *039 none ,048 -006 ,102 -035 *004 *089 woo4 -016 ae 3efore ding. - 16.2' 16.0" 10.40 14-0° 1.5" 11-5O 14.9' 2-80' 8-0' 3.0' 22*OC 12.6" 1.4' .4O 4.w l l .2 C 6.0" 6 4' 4*0° 1*3O 2-00 3.80 24soc 6- 5" 2.5" 6.0' 5 00 1.4' *4" 4.Q0 - 26-4 20-0 23-4 20.0 3.6 18.3 19.1 6*00° 14.5 5.5 25.0 20.0 4.2 2.1 6-44 Nici-oscopical Eramation of Deposit. ANALYSTS. tmorphs.mtr. mvg. orgn satisfactory veg. deb. iiatoms, veg. deb., peal veg. deb., diatoms none satisfactory veg. deb., animal. none lime satisfactory none veg, deb., diatoms veg. deb. ,:diatoms anims A. Ashby. J. Pattinson. Wigner & Harland. W. G. Crook. A. Angell. W. J. Sykes, J. Shea. T. A. Collinge. A. P. Smith. J. Carter Bell. T. P. Blunt. A. W. Angell. Morgan. A. Kitchin. H. Leffmann. AbLreviations:--c., clear; f., faint; h., heavy; p., pale; v. h., very heavy: v. s., very slight. ERRATA.-In the February Table the West Middlesex Free Ammonia should have been -0013 instead of ~0130; Exeter Albuminoid Ammonia should have been -0039 instead of -0004 ; Reading Chlorine should have been -95 instead of 1.95.70 THE ANALYST.THE WORK DONE BY PUBLIC ANALYSTS DURING 1881, UNDER THE SALE OF FOOD AND DRTJGS ACT. In the course of a few days we purpose issuing forms to all Public Analysts, in order to enable us to prepare the tabulated statement ahich we have published for several years past. As the compilation of such a table, vhich is becoming larger and larger every year, necessarily occupies some considerable time, we shall be greatly obliged if analysts will fill up and return the forms with as little delay as possible. DEFENCE ANALYSTS, THE refusal of the Home Secretary to permit a third analyst to be present on behalf of the defence during the analysis of the riscern of Percy Malaolm John, has elicited adverse comments in the public press.The reply of the Home Secretary to Lamson’s solicitor, stating that the application must be refused, as it was contrary to precedent, is of course indefensible. The refmal might, however, have been made on other and better grounds. The Tight course was pursued of having a second analyst present in a case of such a serious nature, In his evidence, Dr. Stevenson stated that it was at his request that Dr. Duprd was appointed to assist. Both of these gentlemen were in the position of independent experts appointed by the Home Office, at the request of the coroner, to assist in the deter- mination of the cause of death ; and they were not responsible to the actual prosecuting authority, via., the Treasury. I t was not until nearly a week after the analyses were entrusted to Dr. Stevenson, that application was made for the presence of a third analyst on Lamson’s behalf, By this time, the analyses must have been well in hand ; and we fail to see what good result could have ensued from the presence of a gentleman responsible only to his employer, the prisoner. Were the rule introduced of having an analyst present on behalf of the defence, grave results might ensue, and the public interests would not be subserved by the change. The third party would usually be introduced at a late stage in the analysis ; he could have no voice in, or control of, the analyses ; his objections might or might not have weight with the official analysts. Moreover, it would be practically imposdble to secure the collective attendance of three analysts eminent in their profession day by day for perhaps two or three weeks. The semblance of injustice done to Lamson by the refusal of the Home Secretary was, we believe, a semblance only ; though we must admit that the refusal was made on quite insufficient and erroneous grounds.-.B&sh Medical Journal.

ISSN:0003-2654    

DOI:10.1039/AN8820700066

出版商:RSC    

年代:1882

数据来源: RSC

摘要:

70 THE ANALYST. LAW REPORTX. Oatmeal Adulteration :- At the Yorkshire West R'iding Police-court recently, Mr. William Heap, grocer, Bentley, watj summoned for having adulterated oatmeal in his possession. Mr. Allen, of Sheffield, the Public Analyst, reported that the meal contained 20 per cent. of other ingredients than the meal producec] from oats. On behalf of the defendant it was strated that Mr. Fairley, a well-known analyst at Leeds, had also analysed defendant's part of the oatmeal, and he stated that it 'IYBS only adulterated to the extent of 6 per cent. No doubt this portion of foreign ingredient had been mixed with the meal when first it mas ground at the mill. The magistrates decided to send the pnrcel of oatmeal atill in the hands of the police for analysis by the Inland Revenlie authorities.Last Saturday the repost from Sonierset House was produced, and it stated that the meal contained 10 per cent. of foreign matter. The defendant said he did not know he was selling adulterated meal, as he sold it as he received it from the millers. A nominal fine of l0s.and 30s. costs W&E imporsea. It mas impossible to get oatmeal free from such ingredients.THE ANALYST. 71 Mark Elvidge, Mill Lane, Burton Road, was summoned by Sergeant Richardson for selling milk which wag not of the nature, substance, and quality demanded. Dr. Harrison, Public Analyst, said the milk had been deprived of one-third of its fat ; it had either been partially skimmed, or else skimmed and new milk mixed. The defendant was fined 15s., including costs. Buutterirte Sold as Butter.-Heavy Fines :- At the Wednesbury Police-court, recently, Mr.Timothy Carter, grocer ana provision dealer, Steel- house Lane, Birmingham, was charged before Mr. W. F. F. Boughey (stipendiary), by Mr. Horder, the inspector under the Sale of Pood and Drugs Act for the South Staffordshire district, with selling butter which was not of the quality and nature demanded by the purchaser. Mr. Stirk, of Wolverhampton, appeared for the defendant. Francis Henry Summerville, an assistant t O Mx. Horder, stated that he had lately visited a stall kept in the Wednesbury Market by the defendant, and asked to be supplied with one pound of butter. An asaistant supplied him with an article which he supposed to be genuine butter, for which he paid Sd.He informed the assistant that the article supplied him would be analysed by the County Analyst, Mr. Jones, and if it were found to be adulterated his employer would be summoned before the magistrate. Upon this the assistant stated that the article supplied was butterine. By Mr. Stirk: He was quite sure that he asked for butter. He was not told that the article before being supplied him was butterine. It was after it was purchased that he was informed it was butterine. It reply to Inspector Horder, witness stated that he had bought butter at 8d. per lb. which the analyst had certified to be pure. Mr. Horder stated that on the 4th inst. he received two packets from the last witness, and he delivered one of them to the County Analyst (Mr. Jones), who had since sent him a certificate to the effect that the article was not butter, and contained less than 1 per cent.of real butter fat, Mr. Stirk said the article was no sold as butter, but as butterine, and as it was supplied by a young assistant, he trusted the Stipendiary would dismiss the case. The Stipendiarx said he considered the case clearly proved, and as it was highly important that the public shonld be supplied with genuine articles, it was necessary that he, as a magistrate, should enforce the law. He considered the present case a bad one, and defendant would have to pay a fine of $5 and $1 14s. 6d. costs. James Powell, grocer, &o., Dudley Port, wag summoned on 9th December for selling adulterated butter, Mr. E. H. Thorne defended. Frss. Summerville, assistant to Mr.J. G. Horder, the inspector under the Sale of Food and Drugs Act, visited the defendant’s shop on the 3rd of November, and asked for llb. of roll butter. A portion of the sample was afterwards analysed by Mr, E. W. T. Jones, analyst, who found that it was a fictitious article, containing only 7 per cent. ot real butter fat. All the other portion was animal fat, made to reprment butter. The article was butterine. For the defence, it was contended that the article was sold as butterine, and the purchaser was told so when he was supplied. Mr. Boughey, after some lengthy remarks on the fraud committed by defendant, and the worthless eharacter of butterine, imposed a fine of $10, and said he ehould impose similar penalties in all these cases. The analysis was-water 6.55, salt 1-32, curd 1.50, fat 90.53.Mrs. PoweII gave him a Bample, for which he paid 1s. Sale of French Co$ee :- At the Cannock (South Staffordshire) Police Court, lately, before Messrs. F. V. Forster, R. H. Briscoe, and 33. Gilpin, Mr. Leonard Adams, grocer, residing at Cannock, was summoned by Mr. J. G. Horder, the inspector under the Sale of Food and Drugs Act, for selling adulterated coffee. Mr. Tanner, of Birmingham, appeared for the defence. Henry Francis Somerville, assistant to Mr. Horder, stated that he visited the defendant’s Bhop on the 16th ult., and asked for a tin of coffee, for which he paid 10d. The contents of the tin were afterwards analysed by Mr. Jones, the County Analyst, and were found to contain 72 per cent. of chicory. In reply to Mr.Tanner, Mr. Horder said he was not aware that French coffee was an extensive article of commerce, When people asked for a pure article they expected to get one. Chicory and coffee could not be looked upon as pure. Mr. Tanner contended that there was nothing fraudulent in connection with the sale, as French coffee mas a well-known article of commerce, containing 28 per cent. of coffee, which was worth 4d., the chicory and the tin making up the value of the whole to 84d. Further, the label ‘‘ French coffee,” protected the defendant from any action. He afterwards proceeded to quote decisions in his favour, and asserted that the magistrates could not legally convict. The Bench decided to dismiss the case ; but the chairman remarked that it was a proper case to bring before the court.Mr. Briscoe said he thought it was only right that the public should know the rubbish they were purchasing. Mr. Horder said he should on behalf of the county authorities appeal against the decision.72 THE ANALYST. Nustard Labelled as a Condiment :- A case of some importmce has lately been disposed of in Scotland, and as it will probably rule similar cases-at least in that part of the kingdom, we give a short note of the matter. An inspector bought a quarter of pound of mustard, and he received a tin, rolled in paper, containing what afterwards proved to be a mixture of mustard and flour, or starch. He mas not told that the mustard was mixed, and although the packet bore a label saying that the contents consisted of mustard and choice condiments, his attention was not drawn to that. He paid 2s. per pound for the mixture, which was understood to be the price of pure mustard. The Sheriff convicted, and fined the defenhnt, who gave notice of appeal to the High Court of Justiciary (Supreme Court in Scotland). The manufacturer, who wlts believed to have something to do with the appeal, was understood to say that similar cases have been dismissed on appeal, and that in point of fact it is necessary to mix mustard with flour or some similar substance to make it keep. Subsequently, however, the defendant vithdrem his appeal against the Sheriff’s decision.

ISSN:0003-2654    

DOI:10.1039/AN8820700070

出版商:RSC    

年代:1882

数据来源: RSC