4 Scientific Proceedings (30J. 



3 (341) 



The behavior of alanin in metabolism. 



By A. I. RINGER anti GRAHAM LUSK. 



[^Proin tlic Physiological Laboratory of the University and Bel/eviie 

 Hospital Medical College?^ 



Injection of 20 grams of ^'-alanin in a completely phlorhizinized 

 dog resulted in the elimination of " extra sugar " in the urine to an 

 amount equalling 18.8 grams, or 93 per cent, of that theoretically 

 possible. Although /-alanin is almost completely convertible into 

 dextrose, preliminary respiration experiments indicate that it does 

 not spare fat metabolism as effectually as docs dextrose itself. 

 This may be due to heat loss in the breaking down of alanin into 

 simpler molecules (formic aldehyde ?) and heat absorption in its 

 construction into dextrose. A similar reasoning would serve to 

 explain Rubner's " specific dynamic action " of protein. 



4 (342) 



An important source of error in Heller's test for urinary 



protein. 



By WILLIAM WEINBERGER. ( By invitation.) 



\Froi)i tJie Laboratory of Biological Chemistry of Columbia Univer- 

 sity, at the College of PJiysicians and Snrgeons.'j 



Heller's test for urinary protein is a fairly reliable one if care 

 is taken in its application, but several urinary protein constituents 

 give uncertain results with it. Thus, mucin fails to yield true pre- 

 cipitation — the " ring" is more or less opalescent and disappears 

 on mixing. With nucleoalbumin the ring is not quite typical and 

 is indistinct in undiluted urine. On the other hand various mis- 

 leading factors, such as resinous acids, must be taken into account. 

 Resinous acids may be ignored, however, if such products as 

 Balsamum Copaivae, or Santal Oil, have not been administered, 

 or if the specific HCl test for resinous acids shows their absence. 

 The turbidity formed with resinous acids dissolves on warming. 

 The acids themselves may be removed by extraction with ether. 

 In concentrated urine, as is well known, a uric acid ring may ap- 

 pear just above the line of junction of the urine and acid, and urea 



