Soluble ferments Digestion. 229 



"starch, dextrine and gum in chemical compositions, consisting as it 

 does of carbon united with hydrogen and oxygen, the latter being in the 

 same proportions as in water. " If the liver be extracted from an ani- 

 mal, and all the blood washed out, and it be then left to itself in a 

 moderate temperature, it will soon be found to contain a quantity of 

 sugar. Moreover, glycogen can be extracted from such a liver, by 

 proper methods. It is also found to contain or secrete a ferment com- 

 petent to split up this glycogen into soluble glucoses. (See Huxley and 

 Youman's Physiology. ) The ferments possessed by the animal organ- 

 ism are, no doubt, the result of a transfer or migration from the vege- 

 table kingdom as is the animal himself. 



Some more of the ferments found in plants may be mentioned. The 

 Emulsin of almonds is an exceedingly vigorous ferment. It is also 

 called synaptase and is extracted from both bitter and sweet almonds. 

 The bitter almonds also contain, in separate cells, a product called 

 amygdalin. This may be extracted in the shape of a crystalline pow- 

 der. If a weak solution of this powder be made, the emulsin has power 

 to split it up into oil of bitter almonds and hydrocyanic acid ( or prus- 

 sic acid ), a deadly poison. The same may be obtained from cherry, 

 laurel, leaves of peach tree, kernels of fruit, apple seeds, &c. 



A like emulsive ferment is found with plants having oleaginous seeds. 

 If such seeds are steeped in water the extract is split into glycerine and 

 a fatty acid. 



There is a ferment contained in Mustard, called Myrosin. It re- 

 solves a substance, which is present in black mustard and is called potas- 

 sium myronate, into glucose and two or three other compounds. There 

 is a ferment in Madder, called Erythrozyme. There is a ferment in 

 . Buckthorne. In the bark of the Aspen there is a glucoside or starchy 

 substance called populin, and in the bark of the Philtyrea latifolia, an 

 evergreen shrub of Southern Europe, there is another called phillyrin. 

 The glucose is separated from either of these by the lactic ferment. 



In gall nuts there is a ferment which operates upon an infusion of 

 the nuts, if left to itself, and causes the tannin to be resolved into glu- 

 cose, and gallic and ellagic acids. 



Pectose is accompanied by a soluble ferment which transforms pec- 

 tose and pectin into pectic and metapectic acids, successively. It oc- 

 curs in various vegetables and fruits and helps the transformation of 

 their natural juices into jellies. 



The soluble ferments all contain carbon, hydrogen, nitrogen and oxygen. But tbeir 

 reactions are different from tbose of the albuminoid substances tbey are associated with. 

 The soluble ferment is not precipitated with tamrn and corrosive sublimate, nor colored 

 by iodine and nitric acid as tin-so substances arc. These ferments are associated with 

 lying organisms, but their actions arc their own and in Icpendent of that of the organ. 

 ism. and they can l>e separated from it. 



Soluble indirect ferments, or zymases, when dry are amorphous, colorless, pulverulent 



