76 B. W. Bull on Emulsine and its Composition. 



liquid was generally filtered from the coagulum as soon as the 

 separation had ensued, and to the filtrate acetic acid was added 

 till no farther precipitate was produced. From the liquid filtered 

 from the precipitate, the emulsine was then thrown down by alco- 

 hol of 85 per cent., a double volume of which I have found ne- 

 cessary. In the alcoholic fluid a small quantity still remains 

 in solution, and a farther addition of alcohol is necessary if the 

 whole amount is desired. For this reason as small a quantity 

 of water as possible has been recommended in preparing the 



emulsion. 



Obtained in this way, and washed with alcohol of 85 per cent, 

 upon a filter with subsequent drying in the air, I have found 

 emulsine very similar in appearance to that described by Mr. Ort- 

 lofF, being a transparent gum-like brittle substance of a dark red- 

 dish brown color, without odor, and not possessing any positive 

 taste. It dissolves with difficulty after maceration in water or by 

 rubbing in a mortar, leaving behind a residue totally insoluble in 

 water, and containing besides phosphates of magnesia and traces 

 of lime, a large amount of organic matter. This insoluble resi- 

 due, after being thoroughly washed with distilled water, still gives 

 distinctly the characteristic reaction of emulsine with amygdaline. 

 The proportion of organic matter which it contains is very vari- 

 able. Four experiments gave me as follows : 



No. 1. No. 2. No. 3. No. 4. 



Organic matter, 56 69-45 59-48 80*27 



Ash, 44 30-55 4052 19 73 



100 10000 10000 10000 



The solution is opalescent, and possesses in the highest degree 

 the property of decomposing amygdaline into bitter almond oil and 

 hydrochloric acid. 



Dried in vacuo over sulphuric acid, it presents very nearly the 

 same appearance. Its color however is not generally as dark, 

 sometimes inclining to a brownish yellow, and at others to a 

 brownish red. When dried with free access of air, it absorbs 

 moisture with avidity while the alcohol is escaping ; if the atmo- 

 sphere is at all damp, and if left upon the filter, it penetrates the 

 pores of the paper in this state, to which it adheres with great 

 tenacity when dry. 



The dark colored appearance of emulsine as obtained in this 

 way, so very different, not only from the almonds themselves, 

 but also from that of the most freshly precipitated substance, 

 which is always white, leads to the conclusion, that while dry- 

 ing, it undergoes some change from the action of the air, which, 



though possibly not affecting its ultimate composition, still would 



render the analysis of a less colored product more satisfactory 



