Local authorities should remember that the Sale of Food and Drugs Act simply applies to the sale of an article not of the nature and substance required, and that articles bad from decomposition should be dealt with under the Public Health Act. This point should also be kept in view by analysts, and if they get a sample of an article which is genuine, but in their opinion decomposed, they should simply return it as genuine in their certificate, and request the inspector to call the attention of the medical officer to the article. Had Mr. Angell and his authority both remembered these points we should have heard nothing of the vinegar case containing microscopic organisms, which was rightly dismissed at Droxford when brought under the Sale of Food and Drugs Act, but with the sale of which the medical officer might have seen fit to interfere had he been notified of it.

RECENT CHEMICAL PATENTS.

The following specifications have been recently published, and can be obtained from the Great Seal Office, Cursitor Street, Chancery Lane, London.

The Chemist and Druggist; The Brewers' Guardian; The British Medical Journal; The Medical Press; The Pharmaceutical Journal; The Sanitary Record; The Miller; Journal of Applied Science; The Boston Journal of Chemistry; The Provisioner; The Practitioner; American New Remedies; Proceedings of the American Chemical Society; Le Praticien; The Inventors' Record; New York Public Health; Philadelphia Printers' Circular; The Scientific American; The American Traveller; Society of Arts Journal.

THE ANALYST.

APRIL, 1880.

75

SOCIETY OF PUBLIC ANALYSTS.

A General Meeting of this Society was held on Wednesday, the 17th instant, at Burlington House, Piccadilly, the President, Dr. Muter, in the chair.

The Scrutineers having examined the voting papers reported that the following gentlemen had been duly elected as Members :

J. G. Tatters, Chemist to the Jarrow Chemical Works, South Shields.

F. P. Perkins, Public Analyst for Exeter.

Elwyn Waller, Ph.D., F.A.C.S., School of Mines, Columbia College, New York.

H. A. Mott, Ph.D., F.A.C.S., 117, Wall Street, New York.

H. Lancaster Hobbs, Analytical Chemist, Holborn Viaduct.

The following gentlemen were proposed for election as Members, and will be ballotel for at the next Meeting :

F. A. Bond, M.B., &c., Brincklow, Coventry.

J. Napier, Public Analyst for West Suffolk, &c.

H. S. Carpenter, Analytical Chemist, Holborn Viaduct.

The following papers were then read and discussed :-

"On a Peculiar Water," by Dr. W. Wallace.

"On the Estimation of Phosphoric Acid in Phosphatic Materials," by A. Smetham, F.C.S., and Mr. Dyer, Mr. Hehner, Dr. Bartlett and others took part in the discussion which ensued, and Mr. Smetham replied.

"On the Work Done during 1879 under the Sale of Food and Drugs Acts," by G. W. Wigner, F.C.S., when Dr. Duprê, Mr. Hehner, and others made some important remarks on the recently issued Report of the Inland Revenue Commissioners.

"The Effect of Light upon some Reagents and Chemical Compounds," by T. P. Blunt, F.C.S.

The President called attention to an abstract in the Journal of the Chemical Society of a paper by Mr. Allen "On the Analytical Examination of Tinctures," which had been read before the Society of Public Analysts and published in THE ANALYST last year. This paper had been reprinted by the Pharmaceutical Journal and of course acknowledged, but the abstractor of the Chemical Society described the paper as being from the Pharmaceutical Journal, thus ignoring both the Society of Public Analysts and THE ANALYST. The President thought the Committee of Publication of the Chemical Society's Journal should have their attention directed to the matter, as this was said to be not the first time such a thing had occurred.

The next Meeting of the Society will take place on April the 14th. at Burlingtou House.

ON THE WORK DONE DURING 1879 UNDER THE SALE OF FOOD AND

DRUGS ACT.

OWING to several of the returns from Public Analysts having been sent in within the past few days, we regret to state that we are compelled to hold over this interesting tabular statement, together with the paper written on the subject until next month; but we may mention that it comprises returns from as many as 200 districts, which is a much larger number than we have been able to include in any previous statement. We are also obliged to postpone until our next number the observations made by members of the Society on the recently issued Inland Revenue Commissioners' Report.

ON THE DETERMINATION OF THE SPECIFIC GRAVITY OF BUTTER FAT AND OTHER SOLIDS AT ORDINARY TEMPERATURES.

BY A. WYNTER BLYTH, M.R.C.S., F.C.S., &c.

Read before the Society of Public Analysts, on 18th February, 1880.

I CONSIDER it far more convenient to take the specific gravity of solid butter fat at 150 than at higher temperatures. My procedure, which has no claim to originality, is as follows:-A short wide test tube is taken, and a little mercury is placed at the bottom, or, which is perhaps more convenient, a lead weight is attached by means of a little wire cage. This is now suspended to the scale-hook by a fine thread of glass and weighed in water, the height of the water in the beaker being noted and kept constant in any subsequent operation.

The same tube is now filled with a weighed portion of the filtered butter fat under examination, and the whole weighed in water. From the data thus obtained the usual calculations are made.

I find that the average specific gravity of Devon butters taken in this way is 9275, whilst butterine is 8467. This method is also excellent for the purpose of determining the specific gravity of a variety of organic solids, whether they be lighter or heavier than water.

If, for example, it is necessary for the purpose of the pathologist to take the specific gravity of kidney or muscle, the tube with mercury is weighed as before, a section of the tissue cut by means of a cork-cutter so that it exactly fits, and, indeed moves rather tightly into the tube, and the surface of the section covered with the mercury and then weighed in water. Should a solid be full of pores, as-for example-bread, it may be placed in a tube, stoppered with a caoutchouc doubly perforated cork, one perforation carrying a thistle head funnel tube, the other a tube for connection with a sprengel. In the throat of the funnel a solid rod is ground airtight, and the mercury

is poured into the funnel. On now completely exhausting the tube of air, the solid stopper is gently loosened and a thin stream of mercury allowed to pour in; thus the solid is completely injected and all errors from air avoided.

ON BLOWPIPE ASSAYS OF SILVER LEAD.

BY F. MAXWELL LYTE, F.C.S.

Read before the Society of Public Analysts, on 18th February, 1880.

IN making blowpipe assays of lead ore, one considerable disadvantage and cause of inaccuracy has always been the extreme minuteness of the button of silver usually obtainable. By the following simple method the whole of the silver may be collected from a comparatively large quantity of ore, so as to be able to obtain a really ponderable button, even before the blowpipe. From one to five grammes of the lead ore to be examined are reduced to fine powder, and treated with strong HCl., and boiled till the whole of the lead has become converted into Pb.Cl2. This usually takes place rapidly. The solution, together with the gangue, is evaporated to dryness on a water-bath, and for each gramme of lead ore which has been employed 50 or 60 c.c. of saturated solution of chloride of sodium is to be added. This being heated to boiling, with the residue of the evaporation of the acid solution of the ore takes up all the Pb.Cl, and the Ag.Cl. The solution is filtered, as hot as possible, into a beaker, or capsule, and the precipitate washed on the filter with a little boiling brine, the washings being added to the rest of the filtrate. Meanwhile a little spongy lead is prepared by reducing a solution of lead acetate with a rod of metallic zinc, and four or five bits of this spongy lead, about the size of peas, are to be added to the hot brine solution and digested with it on a water-bath for a few hours. Such bits of spongy lead will not really weigh altogether more than 04 to 05 grammes, and these will collect all the silver from the solution. The spongy lead should not be compressed when put into the brine, and will float in it, and while they are digested together they should be frequently stirred and agitated with a glass rod. The lead, as soon as placed in the brine, will be seen to change from its blue grey tint to a dull silver grey, and this reaction also affords a delicate test to see when the extraction of the silver is complete. It is only necessary to drop into the solution a fresh morsel of spongy lead, and observe whether it changes colour or not. As soon as the reaction is complete, and all the silver has been withdrawn from solution the argentiferous lead may be collected and fused with Na,CO, on a charcoal support, and finally cupelled; and if properly manipulated, a lead button may be obtained containing all the silver from several grammes of ore, and yet able to be cupelled before the blowpipe. With a little practice the operator will soon find out how to apportion the quantity of spongy lead he employs to the quantity of ore worked on, so as to obtain a button of treatable size, and yet containing ponderable quantities of silver.

ON THE PERSISTENT OCCURRENCE OF STARCH.

BY FRANK P. PERKINS, Public Analyst for Exeter.

Read before the Society of Public Analysts, on 18th February, 1880.

THINGS trivial in themselves occasionally assume a high degree of importance, and in the daily whirl we are too apt to overlook it. There is a substance used extensively by everyone, everywhere, constituting a great portion of our daily food, and yet its very

commonness makes us forget how widespread it is. This substance is starch. Until it is brought home to us in some direct manner we do not bestow a thought on the fact that it is always present with us, and that the dust of our houses, and the air we breathe must contain starch. My attention was first called to what may be named the "Persistent Occurrence of Starch," in rather a notable way. Not many months since I was engaged on a case in which a woman was charged with the murder and mutilation of a child, a case horrible in all its details, the end of which was that the murderess paid the full penalty of her crime on the scaffold. Many articles were submitted to me for examination; among them a chopper, on which was a stain that proved to be not blood, but starch discoloured by iron rust. Another thing was a razor, on which was found blood and starch. I spent some time in endeavouring to solve the problem, How did it come there? Supposing the child had been fed with farinaceous food, and this instrument used in severing the head from the body, would any starch have been likely to adhere to it, and was there any connection between the razor and the chopper? A piece of floorcloth turned up. It had been taken from the mill-stream, and was said to have been the piece in which the child's head was wrapped when it was thrown into the water. It was thoroughly soaked with water and rotten; it had evidently been in the water for a long while, water insects had taken up their abode on it, and were clinging to it. It was minutely examined, but-as might be expected-no blood stains were discovered, but starch again made its appearance-not a few grains here and there, but every part was crowded with granules. It was thickly coated in some places with a black incrustation; this appeared to be nearly made up of starch. I began to open my eyes. This starch had evidently not come from the body. Could the floorcloth have formerly been placed beneath some table on which culinary operations were performed. Full of these thoughts I went to my own kitchen, and transferring a little of the inevitable dust from the matting placed under the table to a glass slide, I submitted it to microscopical inspection; there were the granules of starch plain enough. I was now fully awake. I went to the lobby, and in the dust of the floor starch was present; I went to the stairs, starch was again found. Evidently then, the occurrence of starch in this investigation was but of little value, although that in the child's food bottle afterwards examined was found to be similar in character, and although the woman stated in her confession that the chopper had been used in the way at first suggested, after which she washed it. But what these observations lead to is this, viz: the way in which starch granules are carried or wafted everywhere. I have since examined dust from the floor, and the ledges of the door of my laboratory; freshly deposited dust from a sideboard; dust from high up on papered walls; dust that had settled on new woodwork in a room, dust from the mouldings of the street door, and in every instance starch granules have been identified. The granules have in all cases been confirmed by means of the polariscope, much in the same way as suggested by Dr. Tripe, in his interesting paper in the December number of THE ANALYST ;* and probably starch may be frequently overlooked or species confounded without the aid of this beautiful and useful apparatus. I have thought it worth while to bring these thoughts before you, because I believe the consideration may be applied, and be helpful in discriminating between wilful and accidental adulteration of certain articles of food.

* Vol. iv., p. 221.