THE GENERAL CONSTITUTION OP LIVING BEINGS. 89 



Not one organic molecule in it is identical with itself for 

 two successive instants. There is going on there, in those 

 myriads of capillaries, a work of which we have no concep- 

 tion. These metamorphoses are real chemical equations 

 in action, they are life's mathematical series, analogous to 

 those studied by the infinitesimal calculus. When shall 

 the Leibnitz come who will reveal to us the analytical 

 processes we may apply to that burning blood ? 



However that may be, this mobility of the sanguine 

 fluid is precisely what makes it capable of undergoing 

 modifications of every kind under the influence of miasmatic 

 matters sometimes contained in the air. The albuminoid 

 substance, which is the fundamental part of the blood-com- 

 pound, readily comes into union with poisonous molecules 

 originating without, and, when one point is once affected, 

 the change passes on from neighbor to neighbor, molecule 

 to molecule, throughout the mass. The blood, and after it 

 the most unstable tissues, thus suffer an isomeric modifica- 

 tion which unfits them to discharge their normal functions, 

 and often induces death. In the instance of cholera, espe- 

 cially, the albumen of the blood undergoes a transforma- 

 tion which makes it unable to remain united with the 

 water that keeps it fluid, and brings about its coagulation 

 in the vessels. The fatal consequence is the stoppage of 

 circulation, respiration, and all other vital actions. Robin 

 has also developed very forcibly the idea that there is no 

 such thing as virus, but merely humors grown virulent, 

 which are to healthy humors what common and noxious 

 phosphorus is to red harmless phosphorus, and we know 

 that these two bodies have the same chemical nature. No 

 doubt the secret of virulent and contagious or epidemic 

 diseases, so numerous and so formidable, is nevertheless 

 still undiscovered, but at least we shall now know the 

 direction that it is proper to give to researches, and the 



true meaning of those that may be made. 

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