Society of Biological Chemists XV 
ment with alkali in the cold; (2) that nucleic acid is soluble in 
dilute acetic acid; (3) that nucleic acid is precipitated by mag- 
nesium sulfate in the presence of hydrochloric acid, as proposed 
by Slade. 
Fresh brewer’s yeast is diluted with water and treated with a 
concentrated solution of sodium hydroxide (100 gm. of alkali 
per kilo of yeast) and the solution then partially neutralized with 
hydrochloric acid. The solution is made acid with acetic acid 
and filtered from the separated protein after the bulk of the pre- 
cipitate has settled. The filtration is best accomplished with 
fluted filters or paper pulp. The clear filtrate is treated with 5 per 
cent of magnesium sulfate and enough hydrochloric acid to cause 
the nucleic acid to flock out. The precipitated material is the 
monomagnesium salt and may be dried after washing with alcohol 
and ether. Yield: 4—-7.5 gm. per kilo of yeast. 
The analyses for N, Mg, and P are. lower than the calculated 
figures, but the ratios of the three elements correspond accurately 
with those for monomagnesium nucleate. 
The method is applicable to animal nucleic acid with slight 
modifications. 
STUDIES IN ENDOGENOUS URIC ACID METABOLISM. 
By HOWARD B. LEWIS, MAX 8. DUNN, anv E. A. DOISY. 
(From the Laboratory of Physiological Chemistry of the University of Illinois, 
Urbana.) 
The influence of proteins and various protein derivatives upon 
the hourly uric acid elimination has been studied in the fasting 
subject on a purine-free low protein diet. Protein (egg white, 
cottage cheese) caused a slight rise beginning the 2nd hour after 
ingestion and increasing to a maximum at the 4th hour. Inges- 
tion of equivalent amounts of nitrogen in the form of amino-acids 
(glycocoll, alanine) resulted in a sharp rise the 2nd hour after in- 
gestion followed by a prompt return to the normal level. Ad- 
ministration of a second portion of glycocoll following the return 
to normal caused a like increase in the uric acid excretion. The 
increased uric acid metabolism was not apparently associated 
with the phenomena of specific dynamic action of the glycocoll, 
since aspartic and glutamic acids which probably exert no such 
