8 ANIMAL JUICES. 



The groundless hypotheses of erases and dyscrases stimulated zeal 

 for the chemical investigation of morbid products ; but what have 

 we learnt from the innumerable analyses of morbid blood and urine, 

 beyond the fact that the quantitative proportions of the ordinary 

 constituents of these juices have undergone certain modifications ? 

 As we have but little chance of success, at least for the present, 

 in seeking for deleterious matters, specific contagia, a materia 

 peccans, &c., we should rather direct our inquiries to the elucida- 

 tion of the quantitative relations of the substances known to us, 

 and to their distribution in the different animal juices. But a 

 meagre enumeration of the barren results of chemical analyses in 

 per-centage tables is insufficient for this end, since what we 

 require is to bring these results into harmony with the relations 

 of mass existing between the different animal fluids, and with the 

 amount of motion occurring between the juices that are separated 

 by membranes and cells. If, for instance, we compare the quan- 

 tities of the substances occurring in the secretions during disease 

 with those which remain in the blood, we shall arrive at results 

 yielding the most interesting materials to physiological mechanics, 

 in elucidating the course of morbid processes and the causal 

 connexion existing between entire groups of symptoms, as has 

 been ably shown by C. Schmidt in his admirable investigations on 

 the processes of transudation in cholera, Bright's disease, dysentery, 

 and dropsical conditions. The knowledge of the quantitative 

 relations in which each animal fluid and its individual constituents 

 are formed or secreted, supplies the basis of the statistics of 

 animal molecular motion ; we purpose, therefore, entering into a 

 special consideration of the mechanical metamorphosis of matter 

 in the animal organism, in our third volume, where we shall 

 further endeavour to reconcile the results of the quantitative 

 physiologico-chemical inquiries with the theories of the imbibition 

 of animal membranes, of endosmosis, and of the transudation 

 depending upon the elasticity and thickness of the membranes as 

 well as upon the rapidity of the motion of the blood. Without 

 such points of support, based on physical laws and arithmetical 

 conclusions, few hypotheses regarding nutrition and secretion, and 

 the metamorphosis of the body generally, can attain any degree 

 of logical accuracy. We have therefore regarded it as perfectly 

 falling within the province of physiological chemistry to give 

 the quantity of the matters secreted, and the amount of chemical 

 motion of each animal juice, as far as the state of science enables 

 us to form such estimates. 



