SECRETIONS AND EXCRETIONS. 251 



Examinations of the stools are frequently 



advisable for the purpose of discovering, 



if possible, gall-stones, animal parasites, 



and eggs of parasites. 



If gall-stones, worms, or any other abnor- 



T- mal constituent is to be sought in the stools, 

 STONES, Etc. , ^ „ . , • i • 1 1 



the foUowmg procedure is advisable: 



(i) Have stools for twenty-four or forty-eight hours 



passed into a large vessel. 



(2) Mix each stool with about a gallon of water and 

 stir thoroughly; let stand for one-half hour and then 

 carefully pour off most of the fluid. 



(3) Add more water and mix as before. 



(4) Cover another vessel with surgeon's lint, fastening 

 same with cord or adhesive plaster, and pour the mix- 

 ture upon the gauze. 



In the detritus left upon the gauze, search for gall- 

 stones, parasites, or any other foreign object. In place 

 of the lint, a fine sieve may be used with which to strain 

 the mixture. Gall-stones vary in size from a grain of 

 sand to an olive and larger, and are usually of a brown- 

 ish-green color. They may crumple to the touch, or 

 be quite hard. Often they show the typical smooth 

 facets on one or more sides. The appearance of para- 

 sites and the kinds usually encountered, are described 

 in the chapter devoted to parasites. 



For microscopical examination the feces should be 

 passed into a warmed vessel and sent to a laboratory 



