242 Progress of Rational Pathology. 



or inflammation, the latter of which is more or less superficial, 

 and appears as diffused hypersemia or as an exanthema, accor- 

 ding to the nature of the surface and the quantity of the exsu- 

 dation. Inflammation propagates itself by continuity, partly 

 by the increase of the parasites themselves, partly by sym- 

 pathetic excitement. Only in glanders and syphilis does the 

 contagion propagate itself by lymph and blood. The humoral 

 pathology, which acknowledges only this last mode for the 

 origin and spreading of contagion, overlooks the question, 

 why the contagion should be deposited from the blood exactly at 

 and near the points of inoculation. All diseases of the whole 

 system, i. e. affections of the nervous centres, Henle considers 

 to be the consequence either of local inflammation or of a change 

 in the blood caused by the abstraction of nourishment from it, 

 by the parasites which it contains. The development of con- 

 tagion is dependent on the fixed stages of miasmatico-contagi- 

 ous disease, which again are chiefly the result of external and of 

 accidental circumstances. Metastases are caused by the develop- 

 ment of parasites and of exanthemata internally, under circum- 

 stances which are unfavorable to their development externally. 



Supposing, however, that the hope of discovering parasites, 

 i. e. fungi or infusoria, in the eruptions and the contagions of 

 man may never be realized, yet the hypothesis of the parasitic 

 theory, the assumption of an invisibly small organisation too 

 minute to be distinguished from the animal elements, remains 

 far better, than the assumption of a chemical substance, which 

 js not indicated by any re-agent and cannot be analysed. 

 The contagion of the parasitic theory is not indicated in 

 every case, but it agrees in its operations with those of analog- 

 ous bodies, and explains the symptoms of disease : the conta- 

 gion of the chemical theory is nowhere indicated, it varies 

 from all other known bodies in its supposed operation, and 

 does not explain the phenomena of disease. 



a. Pocks. — Schonlein agrees with those who consider 

 the varioloids to be eruptions specifically different from real 



