proceedings: the chemical society 13 



zone. On White Knob lime-silicate rock is not al)imdant, but in one 

 place it comprises a vein 3 to 5 feet wide which cuts across the marble 

 beds. 



The garnetization of the porphyry is clearly shown at several places 

 in the mine. In one specimen garnet replaces the granite-porphyry 

 along joints and in another as a wave advancing into unfractured but 

 permeable material. In places ore bodies cut directly across the Hme- 

 stone-granite-porphyry contact. Elsewhere garnet-chalcopyrite ore, 

 in bunches of minable size, occurs at the intersection of joints well out 

 in the granite-porphyry. 



These features are believed to indicate: (1) that the garnetization 

 took place after the solidification and fracturing of the inclosing por- 

 phyry, and (2) that, because the limestone blocks were entirely sur- 

 rounded by rigid porphyry at the time of metamorphism, the silica, 

 alumina, and iron of the silicate rock could not have been concentrated 

 from the limestone, but must have been supplied by deeper unconsoli- 

 dated portions of the batholith. 



Adolph Knopf, Acting Secretary. 



THE CHEMICAL SOCIETY 



The 231st meeting was held at the Cosmos Club on November 25, 

 1913. Dr. P. A. Levene, of the Rockefeller Institute of Medical Re- 

 search of New York City spoke on The chemistry of the nucleic acids. 

 He told the story of his own initiation into the study of the chemistry 

 of living tissue, and sketched the early history of the researches on the 

 nucleic acids of protein. It was early estabhshed that the molecule 

 of one of the more complicated of these acids contains two purin bases, 

 two pyrimidine bases, phosphoric acid, and a carbohydrate. The Ger- 

 man investigators directed attention to a simpler acid, inosinic acid, the 

 study of which was taken up by Dr. Levene and his co-workers, with 

 gratif^-ing success. This acid contains hypoxanthin, phosphoric acid 

 and a new pentose sugar, ribose. Further studies showed the relations 

 of these groups in the compound. The successive details by which the 

 structure of the other analogous acids was worked out, both as to the 

 main groups and the structures within the groups, cannot be given in a 

 brief abstract, altho of the greatest interest even to those comparatively 

 uniformed in this complex branch of organic chemistry. 



Discussion. Acree pointed out that the work of Dr. Levene has 

 cleared up the configuration of the pentoses, and emphasized the ul- 

 timate practical importance of these researches. Seidell inquired as to 

 the synthesis of these compounds; Dr. Levene stated that most such 

 efforts have been unsuccessful; furthermore, that their analysis is more 

 important at present than their sj^nthesis. Schreiner gave an apprecia- 

 tion of these researches from the standpoint of the student who wishes to 

 get at the composition of the compounds commonly produced in nature, 

 as against those devised by man. Berg inquired as to the molecftlar 

 weight of the nucleic acids; the simplest has been shown to be probably 



