342 PROTEIN-COMPOUNDS. 



balance, the rising current of air renders the substance to be 

 weighed apparently lighter, and analytical chemistry shows us that 

 hygroscopic substances, after being dried at a high temperature, 

 must be cooled in a closed space over sulphuric acid before their 

 weight can be ascertained with certainty. It is therefore here even 

 more necessary than in the preceding method to repeat the process 

 of weighing, until it yield a constant result. 



When we consider that all the results of the analysis of organic 

 bodies are entirely dependent on the completeness of the drying 

 process, it is obvious that we can attach very little certainty to 

 many of the published analyses of pathological products. Bec- 

 querel and Rodier, who, next to Scherer, have undoubtedly insti- 

 tuted the best analyses of morbid blood, deem it necessary to 

 observe, as something worthy of special notice, that they have 

 devoted the same attention to the quantitative analysis of the 

 blood that is required for an elementary analysis ; although we do 

 not see any reason why less exactness is allowable in the far less 

 controllable analyses of animal fluids, than in elementary analyses. 

 In every analysis, but especially in organic analyses, the utmost 

 care is demanded on the part of the experimenter; and where this 

 is not afforded, the labour will result in nothing better than a loss 

 of time and trouble, and a detriment to science. Indeed most of 

 the analyses made in the department of pathological chemistry 

 have been conducted by chemical dilettanti, who deluded them- 

 selves with the false idea that they were enriching science, and 

 contributing to the establishment of exact medicine by their 

 approximative estimates. It were better for the cause of science, 

 had it never been weighed down by the unprofitable and crude 

 burden of these analyses. 



Physiological Relations. 



Occurrence. Albumen occurs in all those animal substances 

 which supply the whole body, or individual parts of it, with the 

 materials necessary for nutrition and the renovation of effete 

 matters. Hence albumen is a principal constituent of the blood, 

 the lymph, and chyle, as well as of all serous fluids. It also occurs 

 in the fluids of the cellular tissue, in the white of egg, in the 

 Graafian vesicles, &c. It is especially worthy of notice, however, 

 that it is only in the uncoagulated state that albumen is found 

 these parts ; for, as we have already observed, it would be an 

 impossibility, scientifically considered, to distinguish coagulated 



