80 B. W. Bull on Ernalsine and its Composition. 



by exposure to gentle heat. The filtrate possessed a strong 

 acid reaction arising in part from phosphoric acid and partly from 

 an organic substance, a product of the decomposition. On con- 

 centration it formed a syrupy mass, which was uncrystallizable 

 and decomposed by the action of caustic potassa with evolution 

 of ammonia. The solution gave a reaction of sulphur with 



lead salts. 



The filtrate from the precipitate by acetate of lead, contained 

 a large amount of unprecipitated organic matter. The lead was 

 removed from it by sulphureted hydrogen, and the excess of this 

 latter and the acetic acid, as before by gentle heat. The residue 



was a neutral gum-like mass, very soluble in water, and forming a 



___ __ - - A m — — - _ « 



jelly with a solution of caustic potassa. This substance contain- 

 ed nitrogen but no sulphur. Another substance ensues by the 

 decomposition of emulsine by boiling, which is not precipitable 

 by alcohol and is about one-quarter of the amount originally 

 employed. 



Emulsine is entirely precipitated from its solutions by neutral 

 acetate of lead. The filtrate does not give the slightest reaction 

 with amygdaline, while the lead compound, after being washed 

 and brought in contact with that substance, indicates very percep- 

 tibly the formation of bitter almond oil. In this respect my ob- 

 servations agree with those of Ortloff, and give a very simple ex- 

 planation of the failure which has always attended those who 

 have endeavored to prepare this substance after the method recom- 

 mended by Robiquet, viz., "by first precipitating all the other or- 

 ganic matter from an almond emulsion by acetate of lead in excess, 

 and then throwing down the emulsine, from the filtrate by means 

 of alcohol." The statement of Robiquet, that emulsine is colored 

 red by tincture of iodine, is not confirmed by my experience. On 

 the contrary, a precipitate of a yellowish brown color is produced. 

 A solution of emulsine exposed to the air at the ordinary summer 

 temperature, begins to decompose in four or five days with evolu- 

 tion of gas. It becomes turbid, precipitates strongly with ace- 

 tate of lead but not with acetic acid, and for some time does not 

 lose the property of reacting with amygdaline. 



The sulphur in emulsine is indicated by treatment with caustic 

 potassa and subsequent addition of lead salts, as also by fusion 

 with saltpetre and soda. 



If to a solution of emulsine, neutralized with lime water in 

 order to remove the earthy phosphates and prevent the subse- 

 quent presence of phosphoric acid, and afterwards filtered, is add- 

 ed neutral acetate of lead, a bulky precipitate is produced. The 

 precipitate obtained in this way was washed with distilled water 

 and afterwards decomposed by suspending in water and passing 

 through it a stream of sulphureted hydrogen. The resulting 

 liquid, after the acetic acid and sulphureted hydrogen are remov- 





