388 APPENDIX 



fully tested for glucose, and, if present, it must be removed by fermentation with 

 yeast cake. Glucose is rarely present. 



The technic of the reaction requires considerable time, but is easy of manipula- 

 tion, and should be readily carried out in any hospital. The urine, if alkaline, 

 must be made acid in reaction, and any albumin or sugar present must be removed 

 and the urine made up to its original bulk with distilled water. To 40 c.c. of the 

 clear filtered urine are added 2 c.c. of concentrated hydrochloric acid, and the mix- 

 ture gently boiled for ten minutes in a small flask, using a funnel in the neck as a 

 condenser. It is now cooled and distilled water added to again make up the con- 

 tents to 40 c.c., owing to the loss by evaporation. Eight grams of lead carbonate are 

 now slowly added to neutralize the excess of acid. After standing for a few minutes 

 the flask is again thoroughly cooled and the contents filtered until perfectly clear. 

 The filtrate is then well shaken with 8 grams of powdered tribasic lead acetate, and 

 the resulting precipitate removed by filtration, which is repeated until perfectly 

 clear. 



The excess of lead in solution must now be removed by treating with 4 grams of 

 powdered sodium sulphate; the mixture is heated to boiling, then thoroughly cooled 

 and filtered. From the filtrate are measured 17 c.c.; this is transferred to a small 

 flask with funnel condenser and there are added 2 grams of sodium acetate, 0.8 

 grams phenylhydrazine hydrochloride and i c.c. of 50% acetic acid. The mixture 

 is then boiled gently for ten minutes, filtered into a test-tube with a mark showing 

 15 c.c., and made up, if necessary, to that point with hot distilled water. The fil- 

 trate is carefully stirred and left to stand over night. 



The quantity and time of deposit of the crystals will depend upon the degree 

 of extension of the inflammatory process in the pancreas. Thus, in well-marked 

 cases, a light-yellow flocculent precipitate should appear in a few hours, but in less 

 characteristic cases it may be necessary to leave the preparation over night before 

 a deposit occurs. Under the microscope the precipitate is seen to consist of long, 

 light-yellow, flexible, hair-like crystals of pentosazon, arranged in delicate sheaves. 



Urinary Tests in Connection with Acidosis. 



The determination of the ammonia quotient, which is the ratio of N eliminated 

 as ammonia to total nitrogen elimination, has assumed great importance by reason 

 of its connection with various forms of acid intoxication, as in diabetes, pernicious 

 vomiting of pregnancy, and various hepatic diseases. 



The degree of acidosis is better determined by the quantitative estimation of 

 nitrogen elimination as ammonia than by estimating quantitatively the amount of 

 diacetic and /?-oxybutyric acid in the urine. Normally we have about 0.7 gram of 

 ammonia eliminated daily. In acidosis this may rise to 5 or 10 grams and instead 

 of being from 3 to 5% of the total N, it may amount to 30 to 50%. 



Formalin Method for the Estimation of Ammonia. 



Free ammonia reacts with formalin to form hexamethylenetetramine. If 

 sodium hydrate is added to neutralized urine in the presence of formalin free am- 

 monia is liberated and reacts with the formalin. So soon as all the ammonia has 

 been liberated, the end reaction occurs. 



