Important Source of Error in Heller's Test. 



7 



When 5 grams of thymol were administered per os to a medium 

 sized dog, the urine excreted during the succeeding 24 hours 

 showed the familiar brownish yellow color. On standing it grad- 

 ually became black. Heller's test was positive but, as the result- 

 ant precipitate had the same color as the urine, the exact signifi- 

 cance of the result was uncertain. Thereupon different metabolic 

 derivatives of thymol — thymo-sulfuric, thymo-hydrochinon sul- 

 furic and thymo-glucuronic acids were isolated from the urine in 

 the form of their chlorin substitution products. A small quantity 

 of each of these substances was then individually added to normal 

 urine, which in turn was subjected to Heller's test and invariably 

 showed a positive reaction. 



Agitation of such treated urine with petroleum ether in the 

 manner above indicated did not extract thymol-glycuronic acid. 

 This fact is of some importance ; for while petroleum ether readily 

 extracts thymol from urine to which thymol has been added as a 

 preservative, it does not quantitatively extract from urine thymol 

 that has been given internally and which is excreted in combined 

 forms through the kidneys. 



5 (343) 



A clamp for direct transfusion of blood. 

 A demonstration. 

 By ISAAC LEVIN. 



\From the Department of Pathology of Columbia University, at the 

 College of Physicians and Surgeons^ 



The clamp is similar in its construction to an artery forceps 

 without the grooves. At the tip of each blade there is attached a 

 small cannula with a smooth bore. At the inner edge of each can- 

 nula four small pin points are attached, and on the outer surface of 

 the cannula four grooves are cut. When the clamp is closed, the 

 pins of one cannula lie in the grooves of the other. The pins are 

 bent outward and therefore the cannulas have a pyramidal form, 

 so that each pin can lie snugly in its groove. At the beginning 

 of the operation, both halves of the clamp are separated. The 

 vein is pushed through one cannula and its wall is hooked on the 

 pins. The same is done with the artery and the other half of the 



