1895.] MICROSCOPICAL JOURNAL. 319 



tals present will indicate the character of the stone and 

 a careful microscopical examination of the debris present 

 will indicate its position. Stone cannot form in the 

 kidney proper. 



Blood clots cannot form in the bladder in the presence 

 of an equal quantity of urine. Blood may be present in 

 urine and not be perceptible by microscopical examina- 

 tion alone, as when the corpuscles are disintegrated and 

 hsemin is found in solution in the urine. In this condi- 

 tion blood in the urine may be confounded with bile, 

 aniline coloring matter, as in cases of fraud, or by 

 urophsein, or melanin in melanuria, in cases of melanotic 

 cancer of the liver, or by the phosphates. 



When no corpuscles are present in urine which ap- 

 pears to contain blood, by calling in the aid of chemistry 

 we are able to differentiate. We put a few drams of 

 the suspected urine in the test tube and carefully add a 

 few drops of H NOa. If the coloring matter is vegeta- 

 ble, the urine turns yellow; if phosphate it is dissolved, 

 if aniline color it is bleached, if melanin the urine turns 

 dark and rapidly grows darker on exposure to the air; if 

 bile is present we get a. ring with the usual play of 

 colors at the point of contact. But if the coloring mat- 

 ter is hsemin we get a slight precipitation and a slight 

 ring of albumen forms at the point of contact. Then, 

 by the application of Feichmann's test to a fresh sample 

 of the urinary sediment we are able to produce under 

 the microscope the hydrochlorate of hfematin crystals, 

 which is positive evidence of the presence of blood. In 

 tubercular abcess of the urinary tract the bacillus may 

 be found in the urine. 



EXAMINATION OF THE BLOOD. 



There is a number of diseases and diseased condi- 

 tions, diseases of the blood itself, conditions character- 

 ized by abnormal changes in the constituents of the blood 

 or marked variations in its normal constituents in which 



