I9I4] Alfred P. Lothrop 469 



acid was extracted in a Soxhlet app. f or 48 hr. with anhydrous ether. 

 Only 0.00 10 gm. dissolved. The ether was evaporated and the dry 

 residue tested for uric acid by the murexid test with negative results. 

 Uric acid is, therefore, insoluhle in ether. 



Solubility of uric acid in alcohol. Approximately 0.81 gm. of 

 uric acid was extracted with absolute alcohol for 48 hr. The alcohol 

 in the flask became milky due to the Separation of uric acid crystals 

 and at the end of the extraction 0.0260 gm. had dissolved. Think- 

 ing that perhaps there might be some impurity in the uric acid which 

 was soluble in alcohol, the residue f rom the first extraction was again 

 extracted for 36 hours with fresh alcohol and a further loss of 

 0.0197 gm. occurred. A rough estimation, based on the vol. and 

 number of syphonings, gives the solubility of uric acid in alcohol as 

 0.00008 gm. in 100 cc. 



Conclusions. Inasmuch as nearly all tissue analyses are car- 

 ried out by extraction methods a very appreciable amount of urea 

 may be dissolved by ether, although the solubility of urea in ether is 

 probably not much greater than 0.0004 gm. in 100 cc. 



Uric acid is insoluble in ether but is very slightly soluble in 

 absolute alcohol (approximately 0.00008 gm. in 100 cc.) This solu- 

 bility, however, is sufficient to dissolve 0.0260 gm. in a 48 hr. ex- 

 traction. 



Inasmuch as these experiments were made with a Soxhlet app. 

 it seems probable that greater amounts would be dissolved in ex- 

 tractors operating at the temp. of the boiling solvent. 



" Insoluhle " in a biochemical sense should mean no appreciable 

 solubility after a 48 hr. extraction in an extraction apparatus. 



131. Studies on the chemistry of embryonic growth. II. 

 Comparative analyses of the eggs and of the newly hatched 

 larvae of the giant Salamander, Cryptobranchus allegheniensis.** 

 Ross A. GoRTNER. (Biochcm. Lab. of the Station for Exp. Evolu- 

 tion, Carnegie Inst, of Washington.) Analyses of the eggs and 

 larvae of Cryptobranchus included ether-soluble, ether-insoluble but 

 alcohol-soluble, and ether- and alcohol-insoluble (protein) fractions. 

 The nitrogen partition was determined on the first two fractions 

 after boiling for 18 hr. with hydrochloric acid (1.115 sp.g.) and the 



12 For an abstract of the first paper in this series see Proc. Columbia Univ. 

 Biochem. Assoc, Biochem. Bull., 1913, ii, p. 463. 



