IN DISEASES. 461 



such a nature as to justify the establishment of those conclusions 

 and general propositions which were deduced from the results of 

 the analysis ; in the methodological introduction to the first volume, 

 we drew attention to the errors, and the different causes which have 

 given rise to these false deductions. A truly scientific examination 

 of the urine is, however, associated with numerous obstacles and 

 difficulties, and failure may thus frequently attend our efforts, 

 even when all the methods have been employed which present 

 themselves for the prosecution of such an important investigation. 

 The object of such inquiries is obviously that of ascertaining the 

 general properties of the urine and its especial composition in any 

 one definite form of disease: for the urine,, even in health, and 

 still more in disease, is of so variable a nature, that in many cases 

 it is impossible to determine whether the alterations noticed in 

 its condition actually arise from a morbid process, or only from 

 incidental influences. If we carefully observe the changes which 

 often occur in the urine in the course of the same day, not merely 

 in typhus or any abnormally developed acute exanthema, but also 

 in inflammations which are running their ordinary course, we 

 shall clearly see that the urine is regulated much more closely in 

 accordance with the transient condition of the organism, external 

 influences, and simultaneously manifested groups of symptoms, than 

 by the nature of the morbid process. Thus the albumen in the urine 

 in Bright's disease is considerably diminished, and may even almost 

 disappear, if the chronic form of this disease is associated with an 

 affection giving rise to inflammatory fever. The urine which is so 

 characteristic of this form of disease, loses almost all its distinctive 

 properties, and assumes, both in a qualitative and quantitative 

 point of view, the character of inflammatory febrile urine. It 

 appears to us, therefore, to be more rational to limit our examina- 

 tion of the composition of the urine to certain morbid conditions 

 and individual groups of symptoms, and to compare together the 

 various analytical results thus obtained, instead of attempting to 

 extend similar observations to different forms of disease. This 

 method of proceeding is exemplified in the numerous analyses of 

 the urine conducted with such extraordinary perseverance by 

 Becquerel ; for the results of these admirable observations prove 

 less that certain groups of diseases are associated with definite 

 alterations in the proportions of the solid constituents, than that 

 most diseases are attended by very considerable fluctuations in 

 the composition of the urine, depending more upon incidental 

 individual phenomena than upon any special morbid process. 



