THE FAECES 



nized microscopically. The residue may be extracted with cold dilute 

 KOH solution. This extracts bilirubin which may be recognized by 

 Gmelin's test. Pseudo-gall-stones are usually masses of fats, soaps or 

 vegetable material. 



At times enteroliths are mistaken for gall-stone. These are shells of inorganic 

 salts covering inspissated masses of faeces or seeds, etc. 



It is in the faeces we examine either for the parasites or for their ova 

 in connection with practically all the flukes, except the lung fluke and 

 the bladder fluke; for intestinal taeniases and for practically all the 

 round worms, except the filarial ones. 



Bass has recommended that faeces which have been made fluid be centrifuged 

 and the supernatant fluid containing vegetable debris poured off. The sediment 

 contains hookworm eggs. Then pour on sediment a calcium chloride solution of 

 sp. gr. 1050. Again centrifuge and decant. Next add calcium chloride solution 

 of a sp. gr. of 1250 and centrifuge. This brings to the surface the hookworm eggs 

 which may be pipetted off. As a rule, the finding of hookworm eggs is very easy 

 without such a technic. The eggs of Trichostrongylus greatly resemble those of 

 hookworm but are larger, 73 to gi/i long. In perfectly fresh faeces Strongyloides are 

 present as worm-like embryos while hookworm gives only two to four segment eggs. 



In the tropics, the examination of the faeces vastly exceeds in value 

 that of urine and is possibly more important than blood examinations. 



The larvae of various insects may at times be detected in the stools, as well as 

 certain acarines (cheese mites, etc.). 



The test for occult blood is indicated in helminthiases as well as in the conditions 

 for which it is usually tested. 



