ISSN:0003-2654    

DOI:10.1039/AN87802FP056

出版商:RSC    

年代:1878

数据来源: RSC

ISSN:0003-2654    

DOI:10.1039/AN87802BP057

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

THE A N A L Y S T . THE GERMAN GOVERNMENT AND ADULTERATION. THE Questions submitted to the Society of Public Analysts by Dr. Rottenburgh, on behalf of the German Government, together with the Answers of the Society, cannot fail to interest our readers. They show that the steps taken by our legislature, in passing $he Adulteration Acts of 1860 and 1872, aud the Sale of Food and Drugs’ Act of 1875, have proved so far satisfactory in practice that the most powerful of the continental nations intends to follow our leading.Having come to this decision it is also satisfactory that the German Government should apply to our Society as the best exponent of the results obtained by the working of the Acts. We do not wish to imply by this that we alone have advised the Imperial Government on the matter, for we know that the Local Government Board have also given some information, and we also advised the Com- missioner to apply t o the Trades Protection Societies, in orderthat he might ju6ge for himself how slender is the foundation on which their much-talked of grievances rest.On this point we can hardly do better than refer our readers to an extract we reprint from a r e e d leading article in the Grocer.This trade journal has ever been one of the foremost in denouncing analysts and analytical work, and has over and over again spoken of the AdulterationActs as if they mere used simply to harass honest tradesmen. Now, however, its tone is changed ; it appears at last t o hare been educated up to the standard of purity, and directly its education is complete it finds, as we found long ago, that adulteration is rampant. Nothing that we have ever mritten or published in these pages has been such a scathing condemnation of tradesmen as adulterators as the first paragraph from the Grocer’s leading article.We sincerely hope that having got thus far on the road to common sense we may cease to see the Grocer using such childish phrases as “ incom- petent analysts,” and that it will boldly eo-operate with us in the attempt t o suppress adulteration.By doing this all honest traders (and we believe they are the majority) will be benefitted, and dishonest ones mill be ‘( stamped out.” This is a consummation eincerely to be hoped for. Leaving this part of the subject, we consider nest the replies to the questions of Dr. Rottenburgh.Of course man? of these replies are of comparatively minor importance, but there are others which show that the German Commissioner has really put his hand upon some of the defects which still exist in our Act, and has in many cases pointed out as well as we could have done the parts which need amendment. This of course is satisfactory, because the report which he will make to his Government will unquestionably have some weight with our legislature next session in the discussion of the alterations to be made in our own law. The replies to Questions 1, 2 and 3 are of great importance; they embody the principle for which our Society has all dong contended, viz., that analysts should have certain definite limits laid down, according to which it should be their duty to work, and from which there should be no appeal.The present state of things in this country is eminently unsatiafactory. The Society, after long deliberations, adopted a limit in the case of milk which allowed the milk of an ordinary healthy cow to be diluted with fire per cent. of water and yet pass without condemnation ; this in itself was a doubtful proceed-172 THE ANALYST. ing, but the employes at Somerset House have apparently capped it by taking, as a standard, the poorest possible milk that ever man extracted from a cow under any circum- stances, and they have seemingly finally decided that as far as they are concerned average milk with 20 per cent.of added water should be passed as genuine, lest by chance the proprietor of a diseased or underfed cow should accidentally suffer, say once in 20 years.Such a conclusion is, we hold, as lamentable as it is ridiculous, and against all preconceived notions of public morality. We hope that the German Government will not allow this sort of thing to happen, and WQ believe our own will set it right in the Bill to be brought forward next session.The answer to Question No. 10 is also of much importance, and is another of the points which will form a basis of legislation. Nearly all the publicans in London are now labelling their bottles, (‘ This is diluted spirit,” and under the protection afforded by this evasive label they are selling gin and water. Such an abortive result was certainly never contemplated by the Select Committee of 1874.The Questions Nos. 23 and 27 are also important, and in these cases again the replies embody the opinions which have been previously expressed by our Society. The German Commissioner-who had himself been put in communication with the Somerset House authorities-has detected the flaw in the theoretically good idea of making them act as a Court of Appeal, and virtually suggests the reply. It does not nee4 any words of ours to show that as during one year they had only fire samples t o analyse under the Act, that hasty generalisations are all that could be expected. Five minutes of cross- examination is generally enough to dispose of such witnesses.

ISSN:0003-2654    

DOI:10.1039/AN8780200171

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

172 THE ANALYST. SOCIETY OF 1’UBLIC ANALYSTS. Ax Extraordinary General Meeting was held at Burlington House, Piccadilly, on the 7th December, the President, Dr. Dupr6, F.R.S., in the Chair. The Minutes of the previous Xeeting were read and confirmed. Mr. A. Anthony Nesbitt was proposed for election as a member, and Mr. F. W. Gear The Ballot will be taken a t the next Neeting. Mr. W i p e r proposed, and M i .Heisch seconded a resolution c c That the name of the Society be changed, by omitting the word ‘ Public.’ ” The proposal was discussed at great length, and ultimately a division was taken, when it appeared there was a tie, on which Mr. Wigner withdrew the proposal. The Meeting was then made Special, for the purpose of considering the amended Report of the Council in reference t o the replies t o be made by the Society to the questions submitted by Dr.Rottenburgh on behalf of the German Government. The replies suggested were considered seriatim, and after some alterations had been made in them it was proposcd and unanimously resolved that they should be forwarded, as amended, to Dr. Rottenburgh, as the replies of the Society to his questions.Mr. Angel1 exhibited t o the Neeting two pieces of apparatus made by Cetti & Co., one a colorimeter for comparing the colours of waters, and one for the estimation of fat in food stuffs, by washing with ether vapour. The former consists of two long, clear glass tubes, each furnishad with a mirror at the bottom; the tubes when full are closed and Mr. W. J. Williams (assistants to Mr.Wigner), as associates.THE ANALYST. 173 lightly with small pieces of clear glass, by which means all refraction is destroyed, and clear discs of light are produced, by this means a column of three feet in length can be examined for colour and turbidity. The ether extraction apparatus consists of a glass capped funnel, furnished below with a stoppered flask ; the substance, enclosed in a filter paper, is plazed into the funnel, and ether in the flask, the whole is then attached to an upright condenser, and the ether is boiled for two hours, when all fat will be extracted. Nr. Angel1 did not claim any- thing new in the principles involved in these processes, but thought that he had improved the necessary appliances. The next Meeting of the Society of Public Analysts will be held on Wednesday, the 16th inst., at Burlington House, Piccadilly, at 8 o’clook.

ISSN:0003-2654    

DOI:10.1039/AN8780200172

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

THE ANALYST. 173 REPLIES TO THE INQUIRIES BY THE GERMAN GOVERNMENT AS TO TEE WORKING OF THE SALE O F FOOD AND DRUGS’ ACT. THE following are the Questions submitted t o the SOCIETY OF PUBLIC ANALYSTS by DR. ROTTENBURGH, the Representative of the German Government, and the Answers as agreed to at the Special General Meeting of the Society on 7th December last. 1. I s the definition of offences in the Sale of Food and Drugs Act a satisfactory one ? Certainly not ; the definition of our Society should be adopted.See ‘‘ Proceedings of the Society of Public Analysts,” page 2,+ (a copy of which has been sent to DR. ROTTENBURGH.) 2. IS it desirable to define adulteration in relation to a fixed standard of composition for each article of food, or should the definition be a general one? The definition should be general except as regards the articles mentioned in the “ limita,” see “Proceedings ” referred to above, page 2.* Power should be given t o * Extracts from L L PROCEEDINGS OF THE SOCTETY OF PUBLIC ANALYSTS,’) vol.i. p. 2. (a.) I n the case of food or drink. If it contain any ingredient which may render such article injnrious to the health of a consumer, If it contain any substance that sensibly increases its weight, bulk, or strength, or gives it a fictitious value, unless the amount of such substance present be due to circumstances necessarily appertaining to its collection or manufacture, or be necessary for its preservation, or unless the presence thereof be acknowledged at the time of sale.If any important constituent has deen wholly or in part abstracted or omitted, unless acknow- ledgment of such abstraction or omission be made at the time of sale.If it be an imitation of, or be sold under the name of another article. f b . ) I n the case of drugs. If when retailed for medicinal purposes, under a name recognised in the Byitish Phnrmacopcmh, it be not equal in strength and purity to the standard laid down in that work.If when sold under a name not recognised in the British Pharmaeo2mia it differ materially from the standard laid down in approved works on ‘6 Materia Medica,” or the professed standard under which it is sold. De9nition of a@ Adulterated ArticZe.-An article shall be deemed to be adulterated- 1. 2. 3. 4. 1. 2. Linaits.-The following shal! be deemed limits for the respective articles referred to :- Milk shall contain not less than 9 per cent.by weight of milk solids not fat, and not less than Skim milk shall contain nat less than 9 per cent. by weight of milk solids not fat. Butter shall contain not less than 80.0 per cent. of butter fat. Tea shall not contain more than 8 per cent. of miners1 matters, calculated on the tea dried at lOOC, of which at least 3.0 per cent.shall be soluble i n water, and the tea as sold shall yield at least 30 per cent. of extract. 2.5 per cent, of butter fat. Cocoa shall contain a t least 20 per cent. of cocoa fat. Vinegar shall contain not less than 3 per cent. of acetic hcid.174 THE ANALYST. the Home Secretary or some other similar officer as the Central Authority acting on the advice of the Body of Referees to make such additions to those limits as from time t o time might be desirable. 3.Would it be adrisable to have several authorities, with power to fix the standards, or would it be better to have only one Central Authority with that power ? The definition of standards and limits should be embodied in a schedule t o the Act passed by the Imperial Parliament, subject to revision as before mentioned by the Home Secretary or some other similar officer, on the advice of the Body of Referees.4. Suppose an Analyst fixed a certain minimum of standard, e.g., in the case of milk, would not all dealers in milk dilute it down to that standard? Most probably, but no Analyst should have power to fix such a standard without the consent of the Body of Referees.5 . Has the punishment of imprisonmeut often been employed, or has the fine been sufficient ? As far as we are aware imprisonment has only been inflicted in a few cases ; fines, if heavy enough, have generally been sufficient, but in many cases the fines are not heavy enough. 6 . Would it be advisable t9 publish the punishments inflicted ? 7.Would it be advisable, besidea either money-fine or imprisonment, to authorise the Yes, at the discretion of the Court. confiscation of the stock which has been found to be adulterated? Yes, when possible after conviction, at the discretion of the Court. 8. Ought the retail dealer to be compelled to give the name of the wholesale dealer of whom he purchased the adulterated article ? Yes.9. In a case of adulteration found to be iykriozcs t o Izenlth, would it be advisable to 10. 11. 12. 13. 14. 15. provisionally seize the article as soon as the Analyst has given his certificate ? Would it be advisable to state on the label of a mixed article the percentage of that mixture ? Yes, the label should state the maximum percentage of foreign ingredients con- tained in the mixture.Would it be advisable t o make the appointment of an Analyst in every district compulsory ? Certainly . IS it advisable to leave the appointment of an Analyst to the local authority ? Yes, subject to confirmation by the Central Authority. E w e the selected Analysts often been rejected by the Local Government Board ? Very rarely. I n ;what manner should Analysts be paid ? By yearly salary for a fixed number of samples ; an increased payment to be made if more than that number of samples are analysed, at a fixed fee for each such additional sample.I s it advisable to have Analysts’ Districts large or small? Yes, decidedly. Large.THE ANALYST. 175 16. 17. 18. 19 2 0. 21. 22. 23. 24. 2.5. 26. 27. Has it often happened that several local authorities have the same Analyst, and where it is so, has it proved successful? Does i t often occur that a private person prosecutes in adulteration cases? Have the provisions of ssction 14 of the Act proved sufficient ? Have the Analysts’ reports been collected ? results published in abstract.Is it advisable for the Analyet to appear in court, and does that often occur ? on payment to him of a suitable fee, Have the Inland Revenue Chemists often been appealed t o ? Have they often differed from the Public Analysts ? Would it be desirable to have a dift’erent Court of Appeal? A Body of Refeiees should be nominated by the Central Authority, and should consist of Analysts of special experience, t o each of whom should be deputed the reference in all disputed cases as to a particular article of food, drink, or drugs-ie., each referee should have made a special study of some one or more articles, and all disputed cases in reference to those articles should be submitted to him, and he should be liable, on the application of either party, to be called upon to appear in court.Has Sectien %:,of the Act proved successful? Would it be advisable that the Analyst should state in his certificate simply that the article is ‘‘ pure ” or ‘‘ adulterated,” or would it be better to state the nature of that adulteration exactly ? It would be better t o state as exactly as possible the nature and proportion of the foreign admixture.Would it be advisable to empower the police, with the sanction of the magistrate, t o visit suspected beershops, tea stores, factories, &c., to search? It is desirable that the police or other officers should have power to enter places wherein it is suspected that articles of food which are unfit for the food of man are kept.What qualifications should an Analyst possess ? Analysts should be thoroughly educated chemists, of practical experience, possessed of sufficient skill in the use of the microscope, and of some general know- ledge of the more common kinds of poisons and substances injiirious t o health.The chief point, however, is that their education as chemists, &c., &c., should enable them out of their own resources to meet difficulties as they arise, and to recognize clearly all cases in which their own general or chemical knowledge or the authorities available are not sufficient to enable a decided opinion to be pronounced on a sample. It has frequently occurred, and is certainly desirable. Very rarely. They are open to objection, but have answered moderately well. Yes, collected and collated by the Local Government Board and the numerical It is advisable that there should be power for either party to call him if required, It occurs occasionally here. I n a very few instances. I n about half the number of the very few cases referred t o them. Yes, decidedly. No. Quite abortive.

ISSN:0003-2654    

DOI:10.1039/AN8780200173

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

176 THE ANALYST. ON THE EXAMINATION OF HOPS. By W. E. PORTER, F.C.S., &c. HAVING been engaged the last few weclis in making a number of examinations of Hops by the ether process or method, which I published in THE ANALYST for August, 1877, I now send the results of the examination of twelve samples of 1877 or new Hops; these are all what would be called fair samples according to their quality:-F., fine; M., Medium, and L., Low.It will be seen on referring to the 1876 ones,* that the yield of oil, resin, and bitter principle is rather higher than in the new or 1877, the cause of this I believe to be that by age some of the oil is partially oxidised, thereby increasing the weight. 1.-W OBCESTER, F. Noisture . . . . . . . . . Oil, resin, and bitter principle Moisture .. . . . . . . . EAST KENT, F. Oil, resin, &c. . . . . . . 5.-EENT, M. Moisture . . . . . . . . . Oil, resin, &c. . . . . . . 7.-BAVARIA, M. Moisture . . . . . . . . . Oil, resin, &c. . . . . . . Moisture . . . . . . . . . Oil, resin, &c. . . . . . . 9.-sCSSEX, L. 1 ~.-POPERINGHO, L. Moisture . . . . . . . . . Oil, resin, kc,.. . . . . . . . 4.04 14.98 6.15 13.60 8.20 13.27 9.97 13.08 8.55 9.95 10.25 9.25 2.-sPALT, F.Moisture ... Oil, resin, &c. Moisture ... Oil, resin, &c. Moisture .. Oil, resin, &c. &-AMERICAN, M. Moisture ... Oil, resin, &c. Rloiature ... Oil, resin, bc.. .. Moisture ... 4,-~~T0RCESTER, 11. 6.--SUSSEX, If. lo.-sUSSEX, L. 12.-wORCESTER, L. Oil, resin, &c.. .. ... ... ... ... ... ... ... ...... ... 1.. ... ... ... ... ... ... ... ... ... ... ... ... ... The ethereal residues from Nos. 1, 2, and 3 had a bright golden tint, 6.96 14.08 8.10 13.35 7.05 11.75 7 3 7 12.63 9.87 9.23 9.30 8.60 all the others were of a greenish hue. The American was of a dark green tint, and when a few drops of the residue was placed in the palm of the hand and rubbed it gave a strong black currant or cat-like odour-evidently valerianic-probably due to too much heat employed in the drying.The highest yield of oil, resin, &c., was found in Nos. 1 and 2, Worcester and Spalt, both these were dried upon Hopkins’ patent kilns. The Spalt were partially dried in the sun and then brought over and finally dried in these kilns. As the process is interesting, and I believe it to be the right method for drying hops in this country, I may perhaps be allowed to state it.It consists of the ordinary square or rectangular kiln, with two floors instead of one, the lower floor being placed about 18 feet above the fires, the second or upper floor a few feet nearer the roof, in the apex of which, under a cowl, is fixed an exhaust fan. By means of this fan a large current of dry warm air is rapidly and continuously passed through the hops at a temperature which shonld not exceed looQ Faht., enabling the planter to cure his hops without burning them, and without any loss of quality or flavour by the volatilization of the oil, resin, &c.In the process of drying by Hopkins’ plan, the upper floor is loaded with green hops, which are there partially dried, all reek ” being carried off by the fan, no matter how dull or heavy the external * See ANALYST, August, 1877, p.76.THE ANALYST. 177 atmosphere. The upper floor being then opened by a simple apparatus, the partially- cured hops fall gently on to the lower floor nearer the fires, mhere they are thoroughly deprived of moisture by the current of dry warm air (caused by the exhaust fan), and when finished are drawn out from the lower floor on a moveable tray to the bagging chamber, never once trodden upon, unbroken, without the loss of any farina, full of aroma and bright as when picked from the poles.Meanwhile a fresh load of green hops has been put on the upper floor, a duplicate tray replaces the one drawn out, and by the time the hops as described above are finished, the green hops partially dried on the upper floor are again let down, and so the series continues. I have been informed that one or two brewers object t o my process of analysis because it does not estimate the tannin, but this is easily remedied by estimating it in another portion of the hops.No doubt hops that contain a good per centage of tannin hare their value increased as it precipitates the mucilaginous matter in the beer, but the oil, resin, &c., must be of the most value. Out of some number of samples that I have examined I find the tannin to range from 2 to 4.5 per cent.I find some errors are published respecting the constituents of hops, and it is as well to call attention to them, as they have evidently been copied from one source. The analysis of hops is given as- Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.00 Lupulin . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.30 Resin . . . . . . . . . . . . . . . . . . . . . . . . . . . 55.00 Lignin . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.00 Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . .70 100.00 and directly after an analysis is given of the lupulinic grains containing just the same amount ; this of course is a mistake, as hops yield about one-sixth part of these grains ; at this rate the oil, lupulin, and resin would be about; 11.20 per cent., something near what I find to be the mean of the medium and low samples average,

ISSN:0003-2654    

DOI:10.1039/AN8780200176

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

THE ANALYST. 177 NOTES ON WATER ANALYSIS. BY OTTO HEHNER, F.C.S. Read before the Xociety of Pu61ic Analysts on 14th Nbvenderl’, 1877. ALL chemists who have to perform water analysis are aware of the importance of examining samples of water in as fresh a state as possible, in order that change in the quantity of the nitrogenous organic constituents may be avoided. Wanklyn recommends to determine these constituents if possible within 48 hours after the collection of the samples, but 1 was unable to find any record of experiments made with a view to watch the changes which take place when waters are kept for any length of time.Some numerical results may therefore be of interest after the many general statements which have been made. I will touch at the same time one or two other questions in relation to the ammonia- process of water analysis.A sample of very bad water, nnalysed on January 15th, 1877, yidded- Free Ammonia ... ... ... ... ... 0.6640 in 100,000 parts, Albuminoid Ammonia ... ... ... ... 0.0265178 THE ANALYST. The same sample, on September 13th, after eight months, only contained- Free Ammonia.. . . . . . . . . . . . . .. . . . . . . . . 0.0012 Albuminoid Animonia . . . . . . . . . . . . . . . . . . . . . 0.0252 that is to say, the free ammonia had almost entirely disappeared, whilst the albuminoid had remained stationary. A sample of water, taken from the Croydon sewage outfall, yielded in January- Free Ammonia . . . . . . . . . . . . . . . . . . . . . . . . 0.1563 Albuminoid Ammonia . . . . . .. . . . . . . . . . . . . . . 0.0476 Free Ammonia.. . . . . . . . . . . . . . . . . . . . . . . 0.0008 Albuminoid Ammonia . . . . . . . . . . . . . . . . . . . . . 0.0 207 The same sample after being kept for eight months- Water from the Bourne Culvert, at Croydon, in January- Free Ammonia.,. . . . . . . . . . . . . . . . . . . . . . 0.0079 Albuminoid Ammonia . . . . . . . . . .. . . . . . . . . . . 0.0063 And had changed after eight months to- Free Ammonia.. . . . . . . . . . . . . . . . . . . . . . 0.0006 Albuminoid Ammonia . . . . . . . . . . . . . . . . . . . . . 0.0 0 3 7 Water from the Waddon Mill Ponds, near Croydon, directly after being collected- Free Ammonia . . . . . . . . . . . . . . . . . . . . . . . 0.0144 Albuminoid Ammonia., . . . . . . .. . . . . . . . . . . . 0.00 9 9 After eight months- Free Ammonia . . . . . . . . . . . . . . . . . . . . . . . . 0.0169 Albuminoid Ammonia . . . . . . . . . . . . . . . . . . . . 0.0067 Water from the Croydon Pumping Station, taken in January, 1877, yielded- Free Ammonia,, . . . . . . . . . . . . . . . . . . . . . . 0.00 18 Albuminoid Ammonia . . . . . . . . . . . . . . . . . .. . . 0.0018 After eight montlhs- Free Ammonia . . . . . . . . . . . . . . . . . . . . . . . . Nil. Albuminoid Ammonia.. . . . . . . . . . . . . . . . . . . . 0.0020 And, lastly, a Well Water, analysed in January, 1877, containez- Free Ammonia.. . . . . . . . . . . . . . . . . . . . . . . 0.0006 Albuminoid Ammonia.. . . . . . . . . . . . . . . . . . . . 0.0054 And on September 14th, same sample contained- Free Ammonia.. . . . . . . . . . . . . . . . . . . . . . . Nil. Albuminoid Ammonia . . . . . . . . . . . . . . . . . . . . . 0.0065 I n all but one of these cases the free ammonia had almost entirely disappeared, whiist the albuminoid ammonia had either remained stationery or had diminished. Why these changes were so different in the different samples I am a t aloss to explain.As it has been said that distilled water, containing a little free ammonia, after some time, becomes entirely free from it, I thought it quite possible that also the very dilute standard solution of ammonia, or rather of chloride of ammonium, used in water analysis might lose much of its ammonia. To test this I prepmed a new solution of chloride of ammonium and compared its atrength with an old one which had been in use in my laboratory for at least four or five months.Both solutions were found to contain exactly equal amounts of ammonia. It was acertained, also, that the large amount of ammonia contained in the Helenen spring water had not changed to any appreciable extent after a lapse of four months,THE ANALYST. 179 I imagined that Zqe might have had something to do with these changes, especially as it is known that bacteria have the power of reducing nitrates into &rites.I therefore started some series of experiments with a view of ascertaining whether animalcules and other organisms had the power of acting upon or eating up the ammonia. A number of stoppered Winchester quart bottles were filled with ordinary Companies’ London water (28 litres), 1 cubic centimetre of very dilute albuminous urine mas added to each, and to some of the bottles 1 cubic centimetre of a sample of Dutch water, swarming with animal and vegetable life of all kinds.The followipg are the results of the analyses made day by day ;- Date, Nov. 1 ... 2 . 3 ... 4 ... 5 *.. 6 ... 7 ... Date. Oct. 31 ... Nov.1 ... 2 ... 3 ... 4 ... 5 ... 7 ... ... ... ... ... . I . ... ... ... ... ... ... ... ... ... WITHOUT INFUSORIA. Free Ammonia. . . . . . . . . . 0.0149 . . . . . . . . . 0,0133 . . . . . . . . . 0.0161 . . . . . . . . . 0.0126 . . . . . . . . . 0.0319 . . . . . . . . . 0.0348 . . . . . . . . . 0,0345 WITH INFUSORIA. . . . . . . . . . 0.0138 . . . . . . . . . 0,0133 . . . .. .,. 0.0193 . . . . . . . . . 0.0191 . . . . . . . . . 0.0184 . . . . . . . . . 0.0210 . . . . . . . . . 0.0241 Free Ammonia. Albuminoid Ammonia. ... 0.0239 ... 0.0262 ... 0.0234 ... 0.0174 ... 0.0098 ... 0.0061 > ... Albuminoid Ammonia. ... 0.0277 ... 0.0264 ... 0.0229 0.0238 ... 0.0182 ... 0.0153 ... 0.0089 .. During the first two days the composition of the water to which infusoria had not been added remained nearly stationary.On the third day, November 4th, the albuminoid ammonia began to diminish, and suddenly, on November 5th, it had greatly fallen, whilst the free ammonia had risen to nearly its threefold amount. Some allowance must of course be made for the experimental error, unavoidable especially in the case of the determination of ammonia, where we have to deal with exceedingly minute quantities, but on the whole it is certain that the free ammonia increased, whilst the albuminoid substances disappeared.I n the aecond series the changes are far more regular, the free ammonia not rising as high as in the case of the waters to which infusoria had been added, but the general result being the same. These results seem entirely at variance with the figures I have quoted of water8 which had been kept as long as eight months, but it appears from a third series of experiments that on keeping waters for some time the free ammonia in its turn dis- appears, by oxydation or otherwise. Date.Free Ammonia. Albuminoid Ammonia. Sept. 17 . . . . . . . . . . . . . . . 0 0580 ... O.OSl7 Oct. 30 . . . . . . .. . . . . . . . 0.0161 ... 0.0397 Nov. 10 .. . . . . . . . . . . . . 0.0139 ... 0.0279 All these experiments were made in the colder autumn months, and it is probable that the changes would have taken place in a shorter time had the temperature been higher. But yet it seems established that the amounts of both the free and the albuminoid ammonia alter considerably in the course of very few days.As a further instance I may180 THE ANALYST. quote the following results obtained by the analysis of a water sent to me. November 7th it yielded- On Free Ammonia . . . . . . . . . . . . . . . . . . . . . . . . 0.0155 Albuminoid Ammonia.. . . . . . . . . . . . . . . . . . . . 0.0204 On November 10th it had changed to- Free Ammonia . . . . . . . . . . . . . . .. . . . . . . . . 0.0189 Albuminoid Ammonia. . . . . . . . . . . . . . . . . . . . . 0.0186 these results have been checked by duplex determinations. It was formerly generally recommended to add to half a litre of water, to be tested €or free ammonia, either 2 grammes of carbonate of soda or 15 C.C. of a saturated solution of this salt. Water Analysis ” it is stated that this addition may be dispensed with, except in the case of acid waters ; and, I believe, many chemists now altogether omit the use of carbonate of soda.Feeling some doubt as to this point, I made the following experiments :- 500 C.C. of ordinary London companies’ water were boiled in a retort, without any addition until nll free smmonia had distilled over. 10 C.C. of standard chloride of ammonium solution, containing 0.0001 gramme of ammonia, were then added:; the distillation continued until no more ammonia could be detected in the distillate, and the amount of free ammonia which had come over dstermined. Found 0.0192 free ammonia in 100,000 parts of water, instead of 0.020 as added. To decide whether the carbonates of lime and magnesia played any part in this decomposition of the chloride of ammonium solution 10 C.C.of standard solution were added to 500 C.C. of pure distilled water without any further addition being made. The distillate contained 0.0194 ammonia in 100,000 parts of water, instead of 0.023 as added. A similar experiment with distilled water, magnesium chloride, and 0.1 milligramme of ammonia yielded in the distillate 0.0211 ammonia per 100,000 parts of water.Magnesium chloride is therefore without influence upon the result. The addition of carbonate of soda may consequently safely be dispensed with in the case of alkaline waters, and such as contain either carbonates or chlorides of calcium and magnesium. The possibility of distilling all ammonia from such waters, without any addition of carbonate of soda, is therefore solely due to the fact that dissociation takes place in the boiling solution, the ammoniacal salts splitting up, as Fittig has shown i n 1863, into free ammonia, which volatilises with the aqueous vapours and acid remaining in the retort.According to the experiments of Dibbitz (Zutschrif f. anal., Chem. xiii. 4) dilute solutions of chloride of ammonium lose up to 1 per cent., of sulphate of ammonia up to 2+ per cent., and of oxalate of ammonia as much as 24 per cent. of the total ammonia. Acid waters, no doubt, are exceedingly rare, yet I also made an experiment to ascertain the influence of the presence of a strong acid on the determination of the free ammonia. 500 C.C. of pure distilled water were boiled with 0.5 C.C. deci. sulphuric acid, con- taining 2 milligrammes of SOs and 10 c.c., or 0.0001 ammonia, were added. The distillate contained but 0.0011 of ammonia calculated for 100,000 parts. The acid had therefore almost completely retained the, ammonia. I n conclusion, I beg to direct your attention to the graduated tapped nesslerizing cylinders, which I have used for some years past. I find them extremely convenient effecting a great saving of time, trouble and distilled water. Rut in the latest edition of Wanklyn’s

ISSN:0003-2654    

DOI:10.1039/AN8780200177

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

THE ANALYST. 181 SANITA8. So long as the notices of the new disinfectant (‘ Sanitas ” in the various periodicals of the day were limited to the ‘( advertisement ’’ or “ trade notices ” columne, it was not the business of anyone to examine, except privately, its merits or demerits. Now, however, that the representatives of the papers have been invited to inspect its manufacture, and a long article has appeared on it in the leading journal, the matter becomes public property.We purpose, we hope dispassionately, and certainly with no hostile intention, to give our views upon its advantages or otherwise, from a purely scientific point of view. Our remarks will be chiefly directed to ascertain whether or not Mr. Kingzett’s discoveries have made any real advance in practical sanitary science by giving us an agent both cheaper and more active than we already possess.Sanitas consists, essentially, of a dilute aqeous solutiou of camphoric acid and peroxide of hydrogen. To the former its antiseptic, and to the latter its disinfecting properties are mainly due; both these, however, are, we fear, of a comparatively feeble character. Thus, in some experiments, we made an addition of a8 much as 5 per cent.of sanitas to milk, the result being only that it kept it sweet for an extra 16 hours, while additions of 2 or 3 per cent. had no appreciable effect whatever. As an antiseptic, such a dilute solution of camphoric acid may therefore be dismissed from consideration. Its disinfecting power are, we fear, but little higher. The sample (bought a t the rate of 1s.for 5 ounces) contained 0.55 per cent. of peroxide of hydrogen, equal t o 0.26 per cent. of available oxygen, or one volume of sanitas contained 1.82 volume of available oxygen; we are informed, however, that in some samples this proportion rises to 2 volumes. Taking, then, this latter proportion as the basis for our calculation, we find that 1 litre of available oxygen when bought in the form of sanitas, will come to Sd., since we are given t o understand that, a t wholesale price, 1 gallon of sanitas (about 49 litres) could be sold for 6s.* Now the kilo.of per- manganate of potassium can be bought retail for 8s., and contains no less than 175 litres of available oxygen, or at the rate of a little over one halfpenny per litre, As a disin- fecting or oxydizing agent sanitas thus can bear no comparison, a t least in price, to permanganate, and it is a curious illustration of the superior oxydizing power of the latter that the organic matters contained in snnitas, and which are not acted on by the peroxide, are further oxydized by permanganate.A further advantage of the perman- ganate is. that in the solid form, or at its maximum concentration, it is absolutely staple, whereas even dilute solutions of peroxide of hydrogen arc liable to suffer decomposition, and consequent deterioration.One great advantage sanitas certainly possesses over per- manganate, it does not stain, and its being used at all is, we are inclined to believe, entirely due to this fact. Sanitas is an attempt, and we freely confess, a very creditable attempt, to imitate one of the great purifying processes of nature.Mr. Eingzett has, however, overlooked one great factor in this process, or at least he does not enable us to realize it in its entirety. Nature not only makes use of certain agents, but uses them in, practically, limitless quantities, and we are expected to follom her example by using drops where she would employ rivers. Sanitas may have many good qualities, but we fear cost will bar its practical uae. * In our above-mentioned samples of sanitas the litre of available oxygen comes to no less than 4s.

ISSN:0003-2654    

DOI:10.1039/AN8780200181

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

182 THE ANALYST. CORRESPONDENCE. [The Editors are not responsible for the opinions of their Correspondents.] To THE EDITOR OF “THE ANALYST.” Sm,-Referring to the salt in beer question, I think I ought to state that I have several times found as much as 58 and 60 grains salt per gallon in Allsopp’s best quality of pale ale, supplied to my own house in barrels, and I think also in other brands ; and that I long ago, before the passing of the Adulteration Act of ’72, decided not to find fault with any ale which was of good strength, and contained no more than 70 grains per gallon, or 0-1 per cent.Of course this quantity never came enlirely from water, malt, and hops ; but it is not objectionable to use a smnll quantity of salt in extending tha malt. Yours, &c., J.CAMPBELL BROWN. To THE EDITOR OF “THE ANALYST.” M y letter to you, respecting amount of salt in our Beers, of the 23rd October, as published, is totally incorrect as to substance ; the figures are right.THE ANALYST. 183 My assertion and msurance to you should be that none of our Beers that 1 have examined contain salt 50.87 grs. = 20 grs. sodium per gallon ; that our usual brewing waters contain chlorine = to 6.10 or 5.36 grs.sodium ; and that the sample of Beer reported on contained chlorine = to 15.6 grs. sodium. The quantity of sodium found being 15.05 grs. only. Hoping in a day or two to be able to trace the cause of the inaccuracy, when I will write you again and send subscription, I am, Sir, yours faithfully, WILLIAM KIRK, Chemist to the &wton Brewery Company. [Mr, Kirk has since informed us that the incorrections in his first letter to which he refers Were caused by Nome rnbtake in his office-part only of his letter having been sent to US.-ED.ANALYST.] To THE EDITOR OF ‘‘ THE ANALYST.’’ SIR,- On June 2nd, 1876, Mr. W. C. Young gave us an account (Proceedings pp. 159), of some interesting experiments made by him on the volumetric estimation of chlorides in the presence of alkaline phosphates, his very cogent deductions were, that (‘ the volumetric estimation of chlorine in the ash of vinegar, beer, 4‘ milk, or cocoa is affected more or less by the alkaline phosphates present.” Now in the face of this, he on the 14th November, 1877, recommends us to estimate with standard nitrate of silver, the total chlorine, and this in the presence of alkaline phosphates ; if the substance of the former paper is correct, the second must necessarily contain fallacious information, and vice versa.Mr, Young does not in his second paper make any mention of the fact, that he found the phosphates to interfere seriously with the determination. If he had done so one would have inferred that the phosphoric acid has to be removed before the chlorine could be estimated, the method would then become still more complicated.Two quantitative determinations according to Mr. Young are necessary in order to arrive at a qualitative result; namely to decide in the first instance whether a given sample of vinegar, contains sulphuric acid or no. Again in mentioning the methods (( most commonly used for the determination of sdphuric acid in vinegar,” Mr.Young has either completely forgotten Hehner’s method given in August, 1876, (ANALYST, page 105, vol., 1,) or else he has tried it, and finds it not reliable, if the latter, then his experience is diametrically at variance with my own. As far as I have gone I have found Hehner’s method to be quick and reliable, and believe it to be based upon good chemical principles. The qualitative examination of a sample can be conducted in a few seconds, and t.he estimation of mineral acids can be safely made in a reasonable time. Yours, kc., ARTHUR ANGELL.

ISSN:0003-2654    

DOI:10.1039/AN878020182b

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

THE ANALYST. 183 ANALY ST8' BEPORTS. Mr. E. W. T. Jones, Public Analyst for the County of %afford, in his Report for the quarter ending Michaelmas last, states that he examined 207 samples, of which 32 or 16.45 per cent. were adulterated. Theseincludad 4 samples of coffee adulterated with chicory ; 13 of gin, varying from 37.0" to 64.4O under proof; 1 of milk, adulterated with 19 per cent. added water ; 2 samples of mustard contained wheat flour ; 6 samples of oatmeal contained sharps and barley meal ; 1 sample of whisky was 47.49 under proof, and 6 samples of pills were not what they were sold as.Mr. A. J. M. Edger, Public Analyst for the County of Durham, reports that during the quarter ending Michaelmas last he analysed 208 samples. 74 of them being adulterated, viz., 50 samples of various spirits, 2 of oatmeal, 8 of pepper, 6 of soda water, 1 of mustard, 1 of cider, and 7 of milk.The ungenial weather has not damped the ardour, nor abated the contentions of the analysts. Into that troubled region we shall decidedly not venture; it is simply our duty to call attention to the doubts expressed as to the sufficiency of the authorities at Somerset House to be constituted as a Conrt of Appeal, Recent circumstances have deepened those doubts, particularly a dictum pronounced on Burton ale, which stated that strong Burton beers contain about 60 grains of cnmmon salt per gallon, solely derived from the water, malt, and hops used.Naturally the Burton brewers resent the statement, and assure the world that the water used contains from 5.10 groins t o 5-35 grains o f chlorine per gallon ; that no ale leaves the brewery containing 20 grains of salt per gallon ; that in no case is there a concentration to one half, and that salt is not used nor any matters to form it. The general public, moreover, must be credited with common sense-the community at large is not likely to extend its patronage to a beverage which is nothing but a flavoured solution of sodium chloride.-Chemist aliad Druggist.

ISSN:0003-2654    

DOI:10.1039/AN8780200183

出版商:RSC    

年代:1878

数据来源: RSC