SYNAPTASE. 863 



dorous, tasteless, fuses between 194 and 197 (90 and 92 cent.). 

 May be distilled, or dissolved in concentrated sulphuric acid 

 without change. The aqueous solution of potash has no effect 

 upon it, but the alcoholic solution converts it into benzilic acid 

 (Laurent). 



Benzilic acid, HO-f- C 28 H U O 5 ; may be separated from benzi- 

 late of potash by an excess of hydrochloric acid. The acid 

 crystallizes on cooling, in colourless rhombohedrons, of high 

 lustre, or in long prismatic needles. It fuses at 248, and is 

 decomposed at a higher temperature, giving a sublimate of ben- 

 zoic acid, accompanied by violet vapours, and a residue of 

 carbon. It forms a lively crimson solution in cold oil of vitriol. 

 Benzilic acid contains the elements of 2 atoms of benzile and 

 2 atoms of water, one of which remains basic to the acid, and is 

 replaced in the benzilates by a metallic oxide. Benzilate of 

 potash forms large limpid crystals, soluble in water and alco- 

 hol. (Liebig). 



Azobenzo'ide, C 42 H 16 .N 2 4.; a white pulverulent substance, 

 described by Laurent, but of which the composition is rather 

 doubtful. 



Cyanobenzile, a substance which is deposited in transparent, 

 voluminous crystals, when to an alcoholic solution of benzile, 

 one third of its bulk of very concentrated hydrocyanic acid is 

 added, and the whole gently heated. (Von Zinin). 



SYNAPTASE. 



The white of both sweet and bitter almonds consists, in a 

 great measure, of a peculiar matter, very soluble in water, which 

 was named synaptase by M. Robiquet. To prepare it, he 

 directed sweet almonds, from which all the fat oil has been 

 expressed, to be mixed intimately with twice their weight of 

 water, allowed to macerate thus for two hours, and then to be 

 submitted to pressure, which is uniformly increased. The fil- 

 tered liquid contains vegetable albumen, which is thrown down 

 by acetic acid, and gum, which is precipitated by acetate of 

 lead. A liquid remains, which contains some free acetic acid, 

 acetate of lead, sugar and synaptase ; the lead is thrown down 

 by sulphuretted hydrogen, and the synaptase by alcohol, while 

 the free acid and sugar remain in solution. The precipitated 



