MICROSCOPICAL DIAGNOSIS. 49 



be more easily detected by adding to the urine a few drops 

 of a solution of iodine in iodide of potassium; this will give 

 the casts a brownish color. They vary in size from the ^-^ 

 to the ygVfl- of an inch in diameter. The casts have a smooth, 

 waxy, glistening appearance under the microscope. 



Granular casts. Casts may be composed of a large number 

 of granules with but few, if any, epithelial cells. These are 

 found in the early stages of chronic nephritis. They may be so 

 abundant as to form a deposit in the test-tube, if the urine 

 be left undisturbed for a few hours. 



Other casts are sometimes so filled with oil globules that 

 it is all that can be seen at first. This is the case frequently 

 in fatty degeneration of the kidney. Crystals of lime, both the 

 dumb-bell and octahedra, and crystals of the triple phosphates 

 have been seen in casts. 



The presence of epithelial casts in the urine, for a few 

 days only, admits of a favorable prognosis. If pus be mingled 

 with the casts the inflammatory process is of a more severe 

 type. Granular and hyaline casts always indicate a graver and 

 more chronic disease. The greater the quantity of casts, and 

 the longer they appear in the urine, so much the more exten- 

 sive the degeneration and so .much the graver the prognosis. If 

 the casts contain well marked epithelial cells and blood-corpus- 

 cles, and if the granular matter in the casts be of a brown color 

 consisting of disintegrated blood-corpuscles, and if the urine con- 

 tains a large quantity of albumen, then the probabilities are that 

 the case is an acute one. If, however, there are a number of 

 granular casts without any brown color and a number of 

 transparent casts, with a pale color to the urine and a small 

 quantity of albumen, then in all probability the case is a 

 chronic one. 



THE DENSE AND OPAQUE DEPOSIT. 



Pus. The pus corpuscles appear as round, pale, granular 

 bodies, averaging about the T5 Vo' of an inch in diameter. 

 Acetic acid causes them to swell up with a smooth faint out- 

 line, and it develops in their interior from one to four small 

 bodies. After the lapse of a few days the urine completely 

 disintegrates the pus corpuscles. 



