ON THE SPIRIT-VALUE OF A FEW PURCHASED TINCTURES. 
205 
Mr. Deane said the amount of lactic acid in flesh-juice seemed to vary greatly. 
When flesh that was still warm was cut up, hardly any acidity could be detected in its 
juices, but after a short time it became distinctly acid. In the evaporation of flesh-juice 
ammonia was set free at an advanced stage of the process; but a very marked difference 
existed in the amount of this, and he could not say upon what it was dependent. 
Mr. Brady had sometimes thought that the splitting up of triple ammoniacal mag¬ 
nesian phosphate might explain this liberation of ammonia. 
Mr. PooLEY spoke in reprobation of the use of copper vessels in the later stages of the 
preparation of the extract, which was deteriorated in consequence. 
Mr. Reynolds remarked that if the percentage of crystalloid should be accepted as 
the absolute test of value of extractum carriis, it should be accompanied by precautions 
against the artificial introduction of chloride of sodium. Dr. Hassall had published 
analyses of various samples of South American extract, giving in all cases 21*6 to 22 
percent.of ash. Now, in his (Mr. Reynolds’s) experiments, he had found that 16 to 17 
per cent, was the maximum amount of ash, whether in English or in South American 
samples. As to the evolution of ammonia, it certainly might occur, and he had once 
met with it to a very marked degree, but in most cases he thought that the careful 
evaporation of the extract was not accompanied by this evolution. 
Mr. Giles and also Mr. Brough were disposed to attribute the evolution of ammonia 
to the decomposition of some organic nitrogenous principle. 
Mr. Smeeton stated his experience that it was when the heat was unduly raised that 
ammonia was evolved to the greatest extent. 
Dr. Attfield said that, speaking as a chemist, he confessed to surprise at such a phe¬ 
nomenon as the evolution of ammonia from a liquid having an acid reaction. He hoped 
that some one would collect and examine the gas given off. The whole subject was one 
of great interest, and would afford much room for research to any one having leisure. 
Its treatment might properly be subdivided : for instance, after dialysing the solution, 
the crystals obtained could be separated by the use of various appropriate solvents, as 
ether, alcohol, chloroform, benzole, etc., and mechanically by liquids of different den¬ 
sities. 
ON THE SPIRIT-VALUE OE A EEW PURCHASED TINCTURES. 
BY JOHN ATTFIELD, PH.D., F.C.S., 
DIRECTOR, OF THE LABORATORY OF THE PHARMACEUTICAL SOCIETY. 
The value of the spirit in a specimen of a tincture or otlier spirituous pre¬ 
paration depends upon the nature and amount of that spirit. The standard 
of excellence in this respect is, for us, the British Pharmacopoeia. According 
to that book, every tincture should be made with spirit composed of pure 
ethylic alcohol and water, either in the proportion of eighty-four parts, by 
weight, of the former to sixteen of the latter (rectified spirit), or of forty-nine 
parts of the alcohol to fifty-one of the water (proof spirit). The spirit con¬ 
taining sixteen per cent, of water is a common article of commerce; that con¬ 
taining forty-nine per cent, of water is ordered to be made by mixing one 
hundred volumes of the strong spirit with sixty of pure distilled water. These, 
at all events, are the proportions of spirit and water with which the j)roor- 
spirit tinctures of the British Pharmacopoeia are directed to be made. But 
there can obviously be no objection to making proof-spirit by diluting with 
water rectified spirit of any other strength than that just referred to—than 
the “ sixty over proof” (60° O.P.), as it is commonly and very conveniently 
termed. Thus one hundred fluid ounces of a spirit of seventy over prooT”^ 
may have seventy ounces of water added, or the same quantity of a spirit of 
fifty over proof” may have fifty ounces added. In either or any other 
similar case the result will be the true proof-spirit of the British Pharma¬ 
copoeia. These statements may appear trite, but they are made to show that 
