THE GENERAL CONSTITUTION OF 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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