034 LABORATORY HINTS 



(2) Giuelin's reaction. 



Add a few drops of yellow nitric acid to faeces. 

 A display of colours including green is positive. 



(3) Huppert's test. 



Add slaked lime suspended in water to the faeces. 

 Filter, wash and dry the precipitate. 

 Make an extract with hot alcohol and a little HoSOj. 

 Bile pigment gives a green colour. 

 A complete absence of red or green colouring shows absence of 

 bile when icterus is present. When the latter is not present it indicates 

 temporary suspension of bile secretions. In fresh brown stools giving 

 no red coloration there is usually intestinal decomposition. 



When green colouring is macroscopic it indicates too rapid a 

 passage through the colon. 



Urobilin is ahvays present in small quantities 0*03 to o"o6 grm. 

 per diem. Any h^emolytic disease increases the amount, especially 

 malaria. In subtertian it may go up to I'yi grm. or more. 



It is one of the final products of destroyed hb. The smell is due 

 chiefly to indole and skatol. Food materials are absorbed principally 

 in the latter half of the small intestine. In the event of increased 

 peristalsis or catarrh of this part the contents are hurried through 

 without benefiting the patient. Water is absorbed from the large gut, 

 increased peristalsis or inflammation hastens the contents through and 

 gives loose stools, while diminished peristalsis or constipation from 

 any cause means hard fseces due to their remaining too long in the 

 colon and too much water being absorbed. 



The water in an average stool is 75 per cent. Weigh before and 

 after drying. 



Dry over H2SO4 as volatile substances are present and do not heat 

 over 60° C. 



Evaporate ether from bath. 

 Weigh residue = total fats. 



To Examine for Macroscopic Parasites. 



Place the stool in a muslin or fine wire gauze strainer, add water 

 and stir well. 



Repeat with a finer mesh each time and use fresh water. 



The entozoa are readily found. 



For diagnosing helminths and amoebae see section on : " Diseases 

 due to Helminths " and " Amoebic Dysentery." 



MICROSCOPIC. 



Use water with firm stools, but as little water as possible. Cover 

 with a cover-slip and spread out the material by pressure on the slide. 



To distinguish mucus from connective tissue add a drop of acetic 

 acid : fibrous tissue is dissolved and mucus is more distinct. 



