234 PROCEJEDINGS : CHEMICAL SOCIETY 



gated, and the changes characteristic of each have been determined. In 

 the primed leaves there is a loss of 12 per cent to 15 per cent of dry mat- 

 ter, a complete removal of starch and sugar, a loss of from 50 per cent to 

 60 per cent of protein nitrogen and a decrease in malic acid, nicotine and 

 total nitrogen, while there have been increases in the amount of amid 

 and amino nitrogen and citric acid. In case of the stalk-curing method 

 the loss in dry matter is from 25 per cent to 30 per cent; the losses noted 

 by the priming method are also present here, but in addition the effect 

 of translocation comes into play, and we find a very large loss of amid and 

 amino nitrogen and a small loss of mineral matter, while there has been 

 an increase only in the citric acid. Special experiments have shown a 

 marked increase in diastase in the cured leaves. Finally, by curing 

 leaves at different temperatures it has been determined that the rate of 

 increase with the temperature is of the same order as the rate of increase 

 for ordinary chemical reactions. (Author's abstract.) 



W. Blair Clark, of the Office of Sugar Plant Investigations: A 

 laboratory routine auxiliary to sugar beet breeding. This paper presented 

 in detail: (1) Laboratory equipment and arrangements suitable for 

 seed-beet testing; (2) data upon which to base calculations of the work 

 and time required for testing any given number of samples; and (3) data 

 from which it is possible to make a reasonable estimate of the labor cost 

 of such tests. It is believed that the data given will hold, up to 4000 

 tests per day. Above that point it should be possible to introduce 

 modifications productive of still greater economies. 



Discussion. Jodidi discussed the paper, and asked several questions, 

 to which it was replied that the greatest difficulty is to cut a really 

 representative sample from each beet, since the percentage of sugar 

 varies greatly in different parts of the beet. Also that specific gravity 

 has been used only in preliminary selection, and that cold water extrac- 

 tion eliminates most of the non-sugar rotating substances. 



H. Hasselbring, of the Office of Plant Physiological and Fermenta- 

 tion Investigations: Carbohydrate transformations in siveet potatoes dur- 

 ing storage. Cane sugar is not readily used up in respiration, but the 

 invert sugar is consumed, and also some of the starch. The starch 

 transforms to sugar at a higher temperature in the sweet potato than in 

 more northern plants. 



Discussion. Yoder discussed the question of difference in varieties 

 in the North and South. Questions by Jodidi, Gore, and Berg brought 

 out the facts that each analysis is based on 10 kgms; the respiration rate 

 has not been determined ; water was determined by immersing in alcohol 

 and drying off at 78°. 



A special meeting was held at the Cosmos Club on Monday, March 16, 

 jointly with the Washington Academy of Sciences. President Sullivan 

 of the Chemical Society presided. Dr. Wolfgang Ostwald lectured 

 on The chemistry of colloids. The lecture was illustrated with experi- 

 ments and lantern slides. 



Robert B. Sosman, Secretary. 



