20 MORBID URINE. 



horse to rest, was analysed three times by Von Bibra. It 



had the following composition : 



i. n. m. 



Carbonate of lime, . . 80'9 87'2 87'5 



Carbonate of magnesia, . 121 7'5 8*5 



Organic matter, . . 7'0 5 '3 4'3 



100-0 100-0 100-0 



Having entered pretty fully into the chemistry of healthy 

 urine, we must examine the changes which it undergoes 

 in disease, and must ascertain what methods are at our dis- 

 posal for readily detecting the changes. 



We find that in some diseases certain of the normal con- 

 stituents of the urine preponderate, that in others they 

 are diminished in amount or are altogether absent, and some- 

 times we can detect the presence of substances which do not . 

 form part of the healthy secretion. The whole amount of urine 

 excreted may be either increased or diminished in disease. 

 It is diminished in almost all acute and inflammatory diseases; 

 it is increased in a disease termed diabetes, and under the 

 use of diuretic remedies. 



The amount of urine excreted in the twenty-four hours 

 may be increased without there being any augmentation 

 in the solids excreted; the water may be alone in excess. 

 Such urine is light-coloured, and its specific gravity is low. 

 The specific gravity or density of the urine affords us a means 

 }f ascertaining to a certain extent whether the solids be in 

 excess in the urine or not; a very low, specific gravity in- 

 dicates a corresponding deficiency of solids in the sample 

 of urine examined, and the converse holds true. On the 

 other jand, we must not, after merely examining the density 

 ot the urine, and finding it very high, conclude that an excess 



