CHEMISTRY OF THE DIGESTIVE PROCESSES. 
By B. Moore. 
Contents : — Digestive Ferments, p. 312 — Chemical Composition of Digestive Juices, 
p. 342 — Saliva, p. 342 — Gastric Juice, p. 349 — Pancreatic Juice, p. 366— Intes- 
tinal Juice, p. 368— Bile, p. 369 — Digestion of Carbohydrates, p. 392 — Digestion 
of Proteids, p. 428 — Absorption of Carbohydrates and Proteids, p. 430 — 
Digestion and Absorption of Fats, p. 443 — Bacterial Digestion, p. 463— Com- 
position of Fpeces, p. 472. 
The Digestive Ferments, or Enzymes. 
Organised and unorganised ferments. — Fermentation is invariably 
brought about, directly or indirectly, by cell life, either vegetable or 
animal. "When the action is direct, and the chemical changes involved 
in the process occur only in the presence of the cell, the latter is 
spoken of as an organised ferment. When the action is indirect, and 
the changes are the result of the presence of a soluble material secreted 
by the cell acting apart from the cell, this soluble substance is termed 
an unorganised ferment, soluble ferment, or enzyme. 1 
The action of an organised ferment is intimately connected with the 
life of the cell, and is instantly stopped by anything which either kills 
the cell or temporarily arrests its activity ; while that of a soluble 
ferment is not a vital process, but one which is purely physical or 
chemical in its nature. As a consequence, an organised ferment is 
destroyed, and its specific action stopped, by any protoplasmic poison, 2 
while an unorganised ferment, provided it is not precipitated, is un- 
affected by such reagents. 
All the differences in the mode of action of organised and un- 
organised ferments arise from this close connection of the organised 
ferment with the cell. Thus, an organised ferment, provided there is a 
supply of nitrogenous food at its disposal, can grow and multiply in a 
medium in which it is sown, while an unorganised ferment can never so 
increase in quantity ; from this it follows that the rapidity of action of 
an unorganised ferment depends (within limits) on the initial quantity 
added, but in the case of an organised ferment the initial amount soon 
becomes a matter of no moment. 
Organised ferments are unicellular organisms (microfungi), while the 
1 This term was first used by Kiihne, Verhandl. '/. naturh.-med. Ver. zu Heidelberg, 
1S79, N. F., Bd. i. S. 236. 
2 Such as any of those substances commonly known as antiseptics. 
