FERMENTS 11 



take up oxygen from the air in the lungs, nor give it off 

 in the tissues, which hence become asphyxiated. Addition 

 to the blood of such drugs as alcohol, chloroform, quinine, 

 morphine, nicotine, and strychnine, likewise, in various 

 degrees, diminishes the amount of oxygen absorbed, and of 

 carbonic acid given off by the blood. 



It is exceedingly interesting, in this connection, to note 

 how easily the non-nucleated blood corpuscles of the 

 mammalian animal take up, but also give up, oxygen. 

 It would appear that these red blood corpuscles, like the 

 plasma itself, are capable of carrying in loose combination 

 an enormously greater quantity of oxygen than they re- 

 quire for their own special purposes. Leucocytes, on the 

 other hand, nucleated cells, although circulating in the 

 blood have no oxygen carrying power beyond what they 

 require for their own use, the presence of nuclear substance 

 of the cell, in mammals at any rate, appears to be associated 

 with the using up of oxygen rather than with its transporta- 

 tion, and we find that in blood diseases, even where the 

 number of red cells in the blood remains high, the oxygen 

 transporting power of the blood to other tissues may be 

 interfered with by the presence of an increased number of 

 nucleated cells, the leucocytes, this interference varying 

 with the increase. 



FERMENTS BACTERIA BACTERIAL PRODUCTS VACCINES 



FERMENTS determine the healthy nutrition of plants and 

 animals, as well as their decay and many of their diseases. 

 They are exemplified by the yeast which raises bread and 

 converts the starch and sugar of barley into beer or spirit, 

 the rennet which coagulates milk, the filamentous fungus 

 which causes ringworm, and the bacillus which induces the 

 deadly anthrax. Ferments are divisible into two classes : 



1. Enzymes or unorganised ferments are exemplified by 

 diastase, which causes germination in barley and other 

 seeds, ptyalin from saliva, pepsin from the stomach, trypsin 

 from the pancreas, with histozyme, a recently discovered 

 ferment present in blood, and believed to be the chief 

 agent in the reduction of albuminoids. These, like the 



