128 EXUDATIONS. 



answer some of the most pressing questions ; for the most impor- 

 tant substances are precisely those which are conspicuous by the 

 quantity in which they present themselves for observation ; thus, 

 for instance, the insoluble and coagulable protein-bodies, the fats, 

 the collective mass of organic substances soluble only in water, or 

 soluble both in water and alcohol, certain organic acids, and the 

 mineral constituents generally, are perfectly accessible to exact 

 quantitative determinations, as has been recently shown by von 

 Gorup-Besanez* in his admirable treatise on zoo-chemical analysis. 

 As the mineral constituents certainly seem to present a field of the 

 greatest promise, they should be first and especially investigated. 

 We know from the study of the transudations and the animal fluids 

 generally, that the distribution of the potash and soda salts on the 

 one hand, and that of the phosphates and metallic chlorides on the 

 other, is very far from uniform in the different animal juices, and 

 we are almost constrained to follow out this subject more at length, 

 since Graham's investigations have directed our attention to the 

 great inequality in the diffusibility of these substances, and 

 Schmidt's determinations have indicated the difference of the 

 coefficients of condensation of saline solutions when compared 

 with this inequality. The determinations of the organic matters, 

 as for instance, the soluble protein-bodies (accompanied by acids 

 or alkalies) and the fats, will yield far more important results than 

 one might at first sight be inclined to anticipate. If, therefore, 

 the chemist freely confesses his incapacity for the prosecution of 

 qualitative analyses of pathological products, and would gladly 

 abstain from attempting them, he has, on the other hand, before 

 him a vast field of noble, although less arduous labours, with the 

 certain prospect of being able to enrich physiology and pathology 

 with the most brilliant results. 



If the difficulties we have indicated in the qualitative investiga- 

 tion of the exudations deter the chemist from prosecuting such 

 inquiries, he will not fail to perceive the great number of diffi- 

 culties which obstruct his progress when he enters upon the deter- 

 mination of the quantitative relations of the blood, and its more or 

 less abnormal derivatives. Independently of those difficulties, 

 which from the nature of the case appertain to the scientific means 

 employed, external relations necessarily present numerous obstacles 

 in the way of such an inquiry. Although large hospitals and ex- 

 tensive pathological materials are by no means always requisite for 



* Anleitung zur zoochemischen Analyse. Erlangen, 1850, [or Second 

 Edition, enlarged, 1854]. 



