AMYGDALA AMARiE. 249 



the two compounds above named. Disregarding secondary products 

 (ammonia and formic acid), the reaction takes place as represented in the 

 following equation: 



C20H2VNO" + 3OH2=OH^ • 2 (C6Hi20^) • NCH • OWO. 



Crystallized Amygdalin. Anhydrous Hydro- Bitter Almond 



Dextro-glucose. cyanic Acid. OiL 



This memorable investigation first brought under notice a body of 

 the glucoside class, now so numerous. 



Amygdalin may be obtained ciystallized when almonds deprived of 

 their oil are boiled with alcohol of 84 to 94 per cent. The product 

 amounts at most to 2^ or 3 per cent. Amygdalin pe?^ se dissolves in 15 

 parts of water at 8-12° C, forming a neutral, bitter, inodorous liquid, 

 quite destitute of poisonous properties. 



It would appear from the investigations of Portes (1877) that in 

 young almonds, amygdalin is formed before the emulsin. 



When bitter almonds have been freed from amygdalin and fijsed oil, 

 cold water extracts from the residue chiefly emulsin and another 

 albuminoid matter separable by acetic acid. The emulsin upon addition 

 of alcohol falls down in thick flocks, which, after draining, form with 

 cold water a slightly opalescent solution. This liquid added to an 

 aqueovis solution of amygdalin, renders it turbid, and developes in it 

 bitter almond oil. The reaction takes place in the same manner, if the 

 emulsin has not been previoasly purified by acetic acid and alcohol, or 

 if an emulsion of sweet almonds used. But after boiling, an emulsion 

 of almonds is no longer capable of decomposing amygdalm. 



What alteration the emulsin itself undergoes in this reaction, or 

 whether it suffers any alteration at all, has not been clearly made out. 

 The reaction does not appear to take place necessarily in atomic propor- 

 tions ; it does not cease until the emulsin has decomposed about 

 three times its own weight of amygdalin, provided always that sufficient 

 water is present to hold all the products in solution. 



The leaves of Prunus Lauro-cerasus L., the bark of P. Padus L., 

 and the organs of many allied plants, also contain emulsin or a 

 substance analogous to it, not yet isolated. In the seeds of various 

 plants belonging to natiural orders not botanically allied to the almond, 

 as for example in those of mustard, hemp, and poppy, and even in 

 yolk of egg, albuminous substances occur which are capable of acting 

 upon amygdalin in the same manner. Boiling dilute hydrocliloric acid 

 induces the same decomposition, with the simultaneous production of 

 formic acid. 



The distillation of bitter almonds is known to offer some difficulties 

 j-on account of the large quantity present of albuminous substances, which 

 give rise to bumping and frothing. Michael Pettenkofer (1861) has 

 found that these inconveniences may be avoided by immersing 12 parts 

 of powdered almonds in boiling water, whereby the albuminous mattei-s 

 are coagulated, whereas the amygdalin is dissolved. On then adding an 

 emulsion of only 1 part of almonds (sweet or bitter), the emuLsin con- 

 tained in it wiU suffice to effect the required decomposition at a tempera- 

 ture not exceeding 40° C. In this manner, Pettenkofer obtained in some 

 experiments performed with small quantities of almonds, as much as 

 09 per cent, of essential oil. In the case alluded to on the opposite 



