380 THE EFFECTS OF ALLOTROPISM. [MEMOIR XXVII. 



pounds betrays a disposition under trivial causes to as- 

 sume new forms; as with silicic acid so with fibrine, 

 there are two varieties one soluble in water, the other 

 not. A difference of a few degrees of heat turns trans- 

 parent albumen into the porcellanous variety, and analo- 

 gous observations might be made respecting caseine. 



It may therefore be asserted that these proteine bod- 

 ies exhibit a propensity to allotropism in a far more re- 

 markable manner than any other substances known ; not 

 only passing indiscriminately into one another, but also 

 exhibiting special variations under the influence of the 

 most trivial causes. 



And now we may recall the fact that, of the agents 

 which in the inorganic kingdom bring about these 

 changes, the so-called imponderable principles are pre- 

 eminent. I transfer this observation to the case of or- 

 ganized beings, and infer that the nervous system has 

 the power of throwing organized atoms into the active 

 or passive state; that this is the fundamental fact on 

 which all the laws of interstitial death depend ; and that 

 upon this principle its existing allotropic condition 

 an organized molecule either submits to the oxidizing 

 influence of arterial blood, or successfully resists that 

 action. 



But it has been stated that there are certain patho- 

 logical conditions which upon these views meet with 

 a clear explanation conditions which, though long and 

 laboriously studied by physicians, remain involved in 

 contradictions and obscurity. The conditions to which 

 I refer are those known as inflammation and congestion. 



It is agreed among chemists that during the preva- 

 lence of these conditions the urine assumes a peculiar 

 constitution. In inflammatory actions the relative quan- 

 tity of urea and sulphuric acid is much above the nor- 

 mal standard, while in congestive cases the reverse holds 



