B. W. Bull on Emulsine and its Composition. 75 



Ortloff further mentions that a precipitate in a solution of 

 emulsine is a proof that all the alumina was not decomposed, in 

 consequence of the period allowed for fermentation having been 

 too short ; that freshly precipitated emulsine redissolves entirely in 

 water, and after being dried, redissolves, leaving a residue con- 

 sisting of phosphates of lime and magnesia, while the solution 

 contains only traces of inorganic matter. Among other charac- 

 teristics of emulsine according to the above chemist, is that of its 

 being free from sulphur, a conclusion based upon the fact that 

 treated with caustic potassa it does not form sulphuret of potas- 

 sium and continues to precipitate lead salts white ; a result quite 

 at variance with those which I have obtained by a similar 

 treatment. 



A couple of trials in which the above method was followed, 

 did not afford me favorable results. The mixture became quite 

 sour, but even after the lapse of nine days at the given tempera- 

 ture, a filtered portion continued to give a strong precipitate with 

 acid, and on the addition of alcohol, the substance thrown down 

 did not redissolve by the addition of water. After numerous at- 

 tempts, I have found it preferable to prepare emulsine as follows. 

 The finely powdered sweet almonds, already freed from oil by 

 cold pressure, are made into an emulsion with as small a quantity 

 of water as possible. Three times their weight of water is suf- 

 ficient, and with this amount they can be treated twice, using 

 two-thirds of the water at the first, and the remainder at the sec- 

 ond treatment. It should be strained through a linen cloth and 

 the residue both times strongly expressed. The resulting fluid is 

 afterwards to be placed in a suitable vessel and exposed to a tem- 

 perature of 20° to 25° 0. Within twelve hours, if untouched, 

 it separates in two parts. A creamy coagulum, forming perhaps 

 one-fifth of the whole, rises to the top. It is generally of a yel- 

 lowish white color, though sometimes tinged with pink on the 

 surface. The transparent watery fluid nndeneath is light yellow, 

 quite limpid, and after standing two to three days, gives no pre- 

 cipitate with acetic acid. By adding alcohol, a precipitate is ob- 

 tained which entirely redissolves upon the addition of water. If 

 the vessel has not been moved during the process of separation, 

 the coagulum assumes so firm a consistence that the watery por- 

 tion can be almost entirely removed by means of a small syphon, 

 without admixture with the former, in which case it filters very 

 readily. As soon as the separation has taken place, the liquid is 

 ready to be filtered off and precipitated by alcohol. For reasons 

 which will be given below, I do not think it at all necessary for 

 the preparation of pure emulsine that the fluid shall have ceased to 

 be affected by acetic acid, or that the substance thrown down by 

 this reagent should be removed by the addition of it in excess. 



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