462 URINE 



Although the blood may not unfrequently undergo more marked 

 changes from secondary causes than from any essential, morbid 

 process, it retains a stronger impression of these modifications 

 than the urine. This difference may probably depend upon the 

 blood preserving the capacity, even in a morbid condition, of throw- 

 ing off effete matters, if not by the kidneys, by some other 

 medium, whilst the urine retains everything that may have been 

 incidentally generated in the blood and conveyed to the kidneys. 

 . But although these and many other relations may have opposed 

 the efforts of inquirers to discover any constantly recurring pro- 

 perties and admixtures of the urine in individual acute diseases, it 

 might have been hoped that more promising results would have 

 rewarded their labours in the case of chronic disorders, where the 

 change of symptoms is not so rapid as in acute forms of disease. 

 But here, too, our expectations are not realised, chiefly because 

 the deviations from the ordinary composition of the urine are in 

 general more inconsiderable in these conditions than the modifica- 

 tions which depend upon purely physiological relations, such as 

 the nature of the food and other dietetic relations generally. In 

 reply to the question, whether we have actually discovered any 

 distinctive characters in the urine of tuberculous, cancerous, or 

 arthritic patients, it must be admitted that although numerous con- 

 jectures have been suggested which bear the semblance of affording 

 empirical results, we have acquired no facts based upon scientific 

 and exact observations. Thus, for instance, according to Donne, 

 the urine in tuberculosis exhibits a viscid mass of honey-like con- 

 sistence after evaporation, when seen under the microscope ; but 

 has not a similar appearance been observed in other urine? Ac- 

 cording to some observers, arthritic urine is characterised by an 

 abundance of uric acid ; according to others, by a deficiency, or 

 even an absence, of this constituent. Although this striking dis- 

 crepancy may be referred to the vagueness of the term Arthritis, 

 and to an error of medical diagnosis, hundreds of instances might 

 be enumerated in which results scarcely less discrepant have been 

 established by one and the same observer. 



We have here enumerated substances which only occur abnor- 

 mally in the urine. Are not these characteristic of individual pa- 

 thological processes? Albumen, fibrin, oxalate of lime, &c., are not 

 characteristic of specific groups of diseases, but merely of individual 

 processes or groups of symptoms accompanying disease ; we have 

 already endeavoured to show the numerous conditions which 

 may influence the transition of albumen into the urine, and that 



