CLASSIFICA TION. 1 05 



products to which they gave rise. They are accordingly divided 

 into the following classes : 



1. The Proteolytic Ferments. These comprise the animal ferments 

 pepsin and trypsin, various vegetable ferments such as papayotin, 

 and others which may be obtained from germinating seeds of 

 Lupiims angustifoleus, Lupinus luteus, Vicia Faba and Ricinus* 

 major, and certain ferments which may be obtained from bacteria. 

 They all digest the various albumins, with the formation of albu- 

 moses, and some of them also cause the further decomposition of 

 these to amido-acids, hexon bases, etc. 



2. The Amylolytic Ferments. These include the ptyalin of the 

 saliva and the diastatic ferment of the pancreatic juice, the so-called 

 vegetable diastase, and related ferments, which may be obtained 

 from bacteria. Some of these only render starch soluble, while 

 others carry the hydrolysis further to the formation of monosac- 

 charides. 



3. The Inverting Ferments. These are apparently closely related 

 to the amylolytic ferments, and are to a certain extent identical with 

 them. They invert the disaccharides to monosaccharides, and, 

 according to their specific effect upon cane-sugar, maltose, and 

 lactose, are termed invertins, maltases, and lactases, respectively. 

 Such ferments are found in the saliva, the pancreatic juice, and the 

 intestinal juice, in many of the higher plants, and also in numerous 

 organized ferments. 



4. The Steatolytic Ferments. Such ferments cause decomposition 

 of fats into glycerin and fatty acids. Representatives of this order 

 are the so-called steapsin of the pancreatic juice, and analogous fer- 

 ments that have been found in the vegetable world, notably in the 

 seeds of ricinus, Papaver somniferum, Cannabis sativa, in linseed, 

 and in corn. 



5. The Coagulating Ferments. These include the fibrin ferment 

 which brings about coagulation of the blood ; the milk-curdling fer- 

 ment chymosin, which is found in the gastric and pancreatic juice, 

 and a hypothetical ferment which is thought to cause the coagula- 

 tion of myosin. 



6. The ferments which cause decomposition of urea. Such fer- 

 ments are formed by a large number of micro-organisms, such as 

 the Micrococcus urese, the Bacterium ureae, the Bacillus fluores- 

 cens, etc. 



7. Ferments which cause decomposition of glucosides. These are 

 principally found in the higher plants, and include the emulsin or 

 synaptose of bitter almonds ; the myrosin of mustard seeds and 

 other Cruciferse, etc. 



It will be noted that, with the exception of the coagulating fer- 

 ments, all other animal ferments that have thus far been mentioned 

 are ferments which are secreted by the digestive glands, and have, 

 so far as is known, only to do with the digestion of food-stuffs. 

 They are without exception hydrolytic ferments. Of ferments, on 



