INTRODUCTORY REMARKS. 125 



result. On closely considering the question, we certainly find 

 that the quantitative investigation of the exudations justifies us in 

 entertaining far higher hopes, and that it opens to us a rich and 

 varied field of inquiry, while at the same time it affords but little 

 encouragement to the present tendency of physicians towards 

 humoral pathology. We must here rather abide by physical laws, 

 which will afford us the best and securest support in our endeavours 

 to give a more general character to the results of such inquiries. 

 But here we have first to determine the points of view from which 

 such quantitative investigations of pathological products should be 

 considered, as long as our knowledge of qualitative analysis is so 

 deficient. 



We endeavoured, under the head of Animal Juices (vol. ii, 

 p. 308, &c.), to distinguish excessive transudations from exudations, 

 although we did not believe that any very strictly defined line of 

 demarcation could be drawn in individual cases between these two 

 kinds of fluids, which are both exuded from the blood. If we 

 exclude from our consideration the transitional forms, those dif- 

 ferences to which we have referred (see above), and which have 

 been more than sufficiently described by pathologists and histolo- 

 gists in the distinctions between plastic and non-plastic exudations, 

 are rendered sufficiently prominent. We have endeavoured to 

 show, from our own experiments and those of others, that the 

 formation and constitution of transudations depended upon certain 

 physical relations. We think we shall scarcely be in error if we 

 assume that definite numerically reducible relations will be dis- 

 covered for the exudations, by which their composition and subse- 

 quent metamorphosis may be established. In short, no one who 

 is not dazzled by the fantastic forces, which have been supposed, 

 during the last few years, to play so prominent a part in the 

 animal body, can doubt that these exudations are subjected to 

 definite, physically determinable laws. Although the nervous 

 influence may act in a tolerably direct manner upon the chemical 

 relations of the exudation, the quantitative relations must solely 

 depend here, as in all similar processes of the animal body, upon 

 alterations in the mechanical relations. When, therefore, we have 

 investigated the quantitative relations of the products, we shall 

 undoubtedly find enough certain results to give us some insight 

 into the mechanical conditions. It will of course be understood 

 that we do not, in the least, underrate the great theoretical difficul- 

 ties which present themselves in this inquiry ; the task we propose 

 to ourselves is the simple one of solving the question of the 



