ACUTE RHEUMATISM. 241 



any distiu'bance in tlie various steps of these chemical and 

 elemental changes. 



The constancy of the occurrence of structural lesions of the 

 endocardium on the left side of the heart, is by those who 

 hold the theory of the lactic acid origin of rheumatism explained 

 by regarding the final perfecting or development of the morbid 

 agent to occur only in the pulmonic circuit of the circulation. 

 The theory of this origin of rheumatism has received some 

 confirmation from certain experiments in which the injection 

 of various watery solutions of lactic acid into the peritoneal 

 cavity of animals was attended, not with peritonitis, but with 

 certain cardiac changes, as inflammation of the lining mem- 

 brane of the left side, with valvular alterations and fibrinous 

 deposits, and with metastatic affections of the joints. The 

 universal acid condition of the blood and other animal fluids 

 has, however, not been accepted by every observer or experi- 

 menter, some declaring that the opposite condition has in very 

 many instances been found to exist. 



Although we may not be able to state precisely what is the 

 nature of the materies morbi in the rheumatic inflammation, 

 nor yet to explain the mode of its action or development, it is 

 yet tolerably certain that some specific poison, or morbid 

 agent, exists in the economy, most probably as the result of 

 some faulty or deranged activity; and that to the action of this 

 inbred agent, so erratic in the exhibition of phenomena, the 

 product of a constitutional diathesis, the various general and 

 local symptoms owe their origin. 



In the local inflammatory action occurring in acute rheu- 

 matism, it is deserving of notice that although the action may 

 be severe, and the exudation abundant and largely infiltrated 

 amongst the connective-tissue, in the situation invaded, it is 

 rare that the process advances to suppuration ; at least, it is 

 seldom as compared with common inflammation of like severity 

 and extent. Whether the phenomenon of the persistent inva- 

 sion of one class of tissues, the fibro-serous, by the rheumatic 

 poison is always to be accepted as an ultimate fact, the expla- 

 nation of which we may not reach, or whether we are yet, 

 through the investigation of those chemical actions which 

 occur in the animal economy, particularly the relations which 

 subsist between the results of the secondary digestive process, 



16 



