S64 BENZO\L. 



synaptase is washed with alcohol, and dried in vacuo over sul- 

 phuric acid. 



Dry synaptase is described as a yellowish white, opaque, 

 horny mass, hard and friable ; very soluble in cold water. In a 

 fresh solution, iodine produces a deep rose colour, without any 

 precipitate. The solution of synaptase does not keep, but soon 

 becomes turbid from the formation of a white precipitate, and 

 acquires a mouldy odour. It is precipitated from solution by 

 alcohol, in flocks, which redissolve in an excess of water. 

 Acids do not produce a precipitate in its solution; at 140 it 

 coagulates like albumen. It contains azote, and produces am- 

 monia and a new acid in boiling solutions of the alkalies. The 

 composition of synaptase has not been determined. 



A matter which, if a pure substance, is probably the same 

 was obtained by Liebig and Wcehler, and named emulsin, 

 by treating an emulsion of sweet almonds with ether, to take up 

 all the fat oil, and then precipitating the transparent, syrupy 

 liquid which remained, by alcohol, a white matter was abun- 

 dantly thrown down, which formed, when dry, a horny, semi- 

 transparent mass. This substance gives much ammonia when 

 boiled with a solution of barytes or a caustic alkali. There are 

 no means of determining the atomic composition of emulsin, 

 but the following are the results of two analyses of it by Dr. 

 R. D. Thomson and Mr. Richardson : 



Carbon . . . 49.025 48.555 



Hydrogen . . . 7.788 7-677 



Oxygen . . . 24.277 25.026 



Nitrogen . . . 18.910 18.742 



100.000 100.000 



The reaction which occurs when synaptase and the amygdalin 

 of bitter almonds meet each other in solution is very remarkable, 

 and a knowledge of it necessary to enable us to form a conception 

 of the phenomena of the distillation of the bitter almond. I shall 

 state here the latest view of it which has been taken by M. 

 Liebig. On mixing a solution of 10 parts of amygdalin in 100 

 parts of water, with a solution of 1 part of synaptase in 10 

 parts of water, a particular decomposition immediately takes 

 place; the mixture becomes opalescent without losing its 



