DISEASES OP THE URINARY ORGANS. 133 



excess, the food may be given dry, and drinking water may be deficient 

 in amount without any deposition of stone, or gravel. The presence 

 of noncrystalline organic matter in the urine becomes in such cases an 

 exciting cause. Rainey and Ord have shown experimentally that col- 

 loid (noncrystallizable) bodies like mucus, epithelial cells, albumen, 

 pus, blood, hyaline casts of the kidney tubes, etc. , not only determine 

 the precipitation of crystallizable salts from a strong solution, but they 

 determine the precipitation in the form of globular masses, or minute 

 spheres, which, by further similar accessions, become stones, or calculi, 

 of various sizes. The salts that are deposited by mere chemical reac- 

 tion without the intervention of colloids appear in the form of sharply 

 defined angular crystals, and hence the rough, jagged crystals of oxa- 

 late of lime or ammonio-magnesium phosphate. Heat intensifies the 

 action of the colloids in causing precipitation of the dissolved salts, so 

 that the temperature of the kidneys and bladder constitute favorable 

 conditions. Colloids that are undergoing decomposition are also spe- 

 cially powerful, so that the presence of bacteria, or fungi, causing fer- 

 mentation is an important factor. 



In looking, therefore, for the immediate causes of urinary calculi we 

 must accord a high place to all those conditions which determine the 

 presence of excess of mucus, albumen, pus, blood, kidney casts, blood- 

 coloring matter, etc. , in the urine. A catarrhal inflammation of the 

 pelvis of the kidney, of the ureter, or of the bladder, generating excess 

 of mucus or pus ; inflammation of the kidneys, causing the discharge 

 into the urinary passages of blood, albumen, or hyaline casts; inflam- 

 mation of the liver, lnngs, or other distant organ, resulting in the 

 escape of albumen in the urine; disorders of the liver or of the blood- 

 forming functions, resulting in hematuria or hemoglobinuria; sprains 

 or other injuries to the back, or disease of the spinal marrow, which 

 cause the escape of blood with the urine ; the presence in the bladder 

 of a bacterian ferment, which determines the decomposition of the 

 mucus and urea, the evolution of ammonia and the consequent 

 destruction of the protecting cellular (epithelial) lining of the blad- 

 der, or the irritation caused by the presence of an already formed 

 calculus, may produce the colloid or uncrystallizable body that proves 

 so effective in the precipitation of stone or gravel. It has long been 

 known that calculi will almost infallibly form around any foreign 

 body introduced into the kidney or bladder, and I have seen a large 

 calculous mass surrounding a splinter of an arrow that had penetrated 

 and broken off in the body of a deer. The explanation is now satis- 

 factory — the foreign body carries in with it bacteria, which act as fer- 

 ments upon the urine and mucus in addition to the mechanical injury 

 caused by its presence. If such a body has been introduced through 

 the solid tissues, there is, in addition, the presence of the blood and 

 lymph derived from the wounded structures. 



