696 THE LIFE AND WORKS OF BROWN-SEQUARD. 



the name of opotherapy, or treatment by organic extracts. Extracts 

 from the pancreas, tbe liver, the suprarenal capsules, the spinal cord, 

 the ovary, the prostate, the testicle, tbe thyroid gland, have thus been 

 successively used in therapeutics with varying degrees of success. 



The study of the thyroid extract especially has led scientists to the 

 most unmistakable results. 



This subject has not failed to extend itself still further. In fact, the 

 preparation and effects of these various extracts have come to be con- 

 founded with serotherapy or the treatment by serums, modified for the 

 purpose of combating diphtheria and various other diseases. The old 

 inoculation of the virus of smallpox and the vaccination of Jenner have 

 been brought under the same category of ideas. But it is beyond the 

 limits of the present notice to try to state, even in a summary manner, 

 the developments, every day more extensive, of the new doctrines and 

 therapeutic methods. Under their influence the theory of germs is 

 itself undergoing profound modifications, which tend to change the 

 views which were at first held. Not only are the effects produced by 

 microbes upon living organisms referred more and more to the domain 

 of chemistry, and considered as independent of life, but the real agents 

 that cause these phenomena are no longer supposed to be the microbes 

 themselves. Accordiug to the new doctrine it is not the microbe that 

 acts by virtue of its own life, carried on either with or without the 

 assistance of air, in producing the phenomena of disease or of fermen- 

 tatiou; but, as I formerly thought, if 1 may be permitted to cite 

 myself, the real agents of all these phenomena are chemical agents, 

 properly so-called, secreted by the microbes, yet distinct from them. 

 These are immediate definite principles belonging to the class of the 

 alkalis or the amides, that act either as toxines or antitoxines, accord- 

 ing to circumstances. 



In this way there tends to be formed an entirely new system of phys- 

 iology and of practical treatment of disease, a system which recalls in 

 some respects, and in certain of its methods, the primitive conceptions 

 and eveu the superstitions of the early days of medicine. We certainly 

 do not wish to fetter ourselves with the formulas of such a system any 

 more than with those of the old ideas concerning the spiritual cause of 

 disease and the vitality of miasms, or with those of the recent theories 

 of the necessary and universal influence of microbes in pathology. 

 Modern science does not become petrified in any dogmatism; but its 

 incessant evolution is regulated by the very succession of discoveries 

 accomplished accordiug to its methods. Now, it is certain that the 

 study of the internal function of glandular cells and that of the secre- 

 tions of microbes has become to-day the point of departure for an 

 entirely new set of therapeutic procedures; unknown ways have been 

 opened by these discoveries for physiology and the medical sciences. To 

 Browii-Ssquard will be given the glory of having been one of the con- 

 querors in this new domain. 



