8 PHYSIOLOGICAL CHEMISTRY. 



The processes taking place in the living muscle yields an example 

 of this kind. A removed muscle, which gives no oxygen when in 

 a vacuum, may, as HERMANN has shown, work, at least for a time, in 

 an atmosphere devoid of oxygen, and give off carbon dioxide at the 

 same time. 



We call processes of splitting which are accompanied by a de- 

 composition of water and then a taking up of its constituents (H 3 

 and 0) hydrolytic splittings. These splittings, which play an im- 

 portant role within the animal body, and which are most frequently 

 met with in the process of digestion, are, for example, the trans- 

 formation of starch into sugar and the splitting of neutral fats into 

 the corresponding fatty acid and glycerin. 



(^.(C..^/).). + 3 H,0 = 0,H 6 (OH), + 3(C IS H S6 0,). 



Tristearin. Glycerin. Stearic acid. 



As a rule the hydrolytic splitting processes as they occur in the 

 animal body may be performed outside of it by means of higher 

 temperatures with or without the simultaneous action of acids or 

 alkalies. Considering the two above-mentioned examples, we know 

 that starch is converted into sugar when it is boiled with dilute 

 acids, and also that the fats are split into fatty acids and glycerin 

 on heating them with caustic alkalies or by the action of super- 

 heated steam. The heat of the chemical reagents which are used 

 for the performance of these reactions would cause immediate 

 death if applied to the living system. Consequently the animal 

 organism must have other means at its disposal which will act 

 similarly, but in such a manner that they may work without 

 endangering the life or normal constitution of the tissues. Such 

 means have been recognized in the so-called formless ferments or 

 enzymes. 



Alcoholic fermentation, as well as other processes of fermenta- 

 tion and putrefaction, is dependent upon the presence of living 

 organisms, ferment fungi and splitting fungi of different kinds; and 

 according to the researches of PASTEUR, these processes are to be 

 considered as phases of life of these organisms. The name orga- 

 nized ferments OT ferments has been given to such micro-organisms 

 of which ordinary yeast is an example. However, the same name has 

 also been given to certain bodies or mixtures of bodies of unknown 



