ITS CHEMICAL CONSTITUENTS. 403 



of this secretion in its morbid state. In those acute diseases in 

 which, on account of an antiphlogistic diet, only small quantities of 

 animal food are taken, the secretion of the phosphates is very much 

 diminished, as compared with that of the urea in the normal state. 

 Heller, who has made important observations on the variations in 

 the quantity of the phosphates, considers that they are increased 

 in rheumatism and diseases of the ear, and diminished in acute and 

 chronic spinal affections, neuroses, and in acute and chronic diseases 

 of the kidneys. 



If any evidence could be drawn from one observation, I might 

 be induced to believe that there is an excessive secretion of the 

 earthy phosphates by the urine in rachitis. A thoroughly rachitic 

 child, aged four years, discharged by the urine, which was very acid 

 and contained oxalate of lime, as much as 0*496 of a gramme of 

 the phosphates in twenty-four hours ; whilst another child of the 

 same age, and who, like the first, had been fed principally upon 

 milk, with some meat and white bread, secreted 0*345 of a gramme 

 in the same period. 



Iron is verv commonly present in small quantities in the urine, 

 although it is sometimes absent in this fluid in healthy persons. There 

 has been much difference of opinion as to whether or not the urine 

 in chlorosis contains iron; but this question might easily have been 

 settled, if more practicable methods had been employed for detect- 

 ing the iron. According to my own observations, iron occurs in 

 the urine of chlorotic patients as well as in that of healthy persons, 

 although it may in some cases be entirely absent ; as the urine in 

 chlorosis is generally poor in solid constituents, it is necessary to 

 employ a large quantity of this secretion in order to detect its 

 presence. It is, however, worthy of notice, that after the use of 

 ferruginous preparations, whether employed in chlorosis or any 

 other disease, iron may be detected in fresh urine, either directly 

 by the ordinary reagents, or only in small quantities in the ash of 

 the urinary residue. I have been unable to determine the relations 

 which induce such an increased activity in the resorption of the 

 iron as to enable larger quantities of it to pass into the urine. 



A small quantity of silica may also be found in the urine, as 

 was shown by Berzelius (see vol. i., p. 426). 



The urine likewise holds in solution gases, namely, carbonic 

 acid (Marchand*), with a little nitrogen. Both admit very readily 

 of being exhibited by the method described at p. 330. 



The quantity of water in the normal urine is so exceedingly 



* Journ. f. prakt. Ch. Bd. 49, S. 250. 



2 D 2 



