344 



SCIENCE 



[N. S. Vol. XXXIII. No. 844 



" The Fermentation of Citric Acid in Milk," 

 A. W. Bosworth and M. J. Pruclia. 



" Studies on Tiiermal Deatli-points of Milk En- 

 zymes," W. N. Berg. 



" Studies upon the Extractives of the Maize 

 Embryo," C. L. Alsberg. 



" A Rapid Method for the Production of Im- 

 mune Sera," J. P. Atkinson. 



" Plants which Require Sodium," W. F. V. 

 Asterhout. 



" Inosinic Acid," P. A. Levene and W. A. Jacobs. 



" Yeast Nucleic Acid," P. A. Levene and W. A. 

 Jacobs. 



" The Distribution of Nuelearidases in Animal 

 Tissues," P. A. Levene and F. Medigreeean. 



Dissolved Oxygen as an Index of Pollution: Geo. 



A. SoPEE and Payne B. Parsons. 



The determination of dissolved oxygen as an 

 index of sewage pollution has been found to be 

 reliable in the work of the Metropolitan Sewerage 

 Commission of New York, where the quantities of 

 sewage and conditions attending the discharge of 

 sewage were determined and other factors in the 

 problem known. 



Opinions differ as to the permissible limit of 

 exhaustion of oxygen by sewage. Some authori- 

 ties consider that more than 30 per cent, should 

 not be taken from the water. Others have ex- 

 pressed the opinion that 70 per cent, was a per- 

 missible draft. To the present authors it appears 

 that no arbitrary standard can safely be estab- 

 lished. A careful consideration of the local con- 

 ditions should determine the safe limit for any 

 case. 



Abstracts for the following papers have not 

 been received: 



" Chemical Study of Wheat— Part 2," G. B. 

 Frankforter and Ben Hur Kepner. 



" The Composition of some so-called Malt- 

 tonics," Julius Hortvet. 



" The Examination of Beverages for Caffein and 

 other Alkaloids," Edwin DeBarr. 



" The Soluble Carbohydrates in - Asparagus 

 Roots," Fred W. Morse. 



" The Examination of some California Alfalfa," 

 M. E. Jaffa. 



" Sugar By-products," Herbert M. Shilstone. 



" Coffee and Coffee Substitute Extracts," Floyd 

 M. Robinson. 



" The Relative Toxicity of Substances added to 

 and occurring Naturally in Foods," A. N. Cook. 



" Quantitative Method for Determining Non- 

 volatile Oil in Cereals," E. H. Harding and Miss 

 Lilian Nye. 



DIVISION OP AQEICULTUEAL AND FOOD CHEMISTET 



H. E. Barnard, chairman 

 B. E. Curry, secretary 

 Preliminary Report on the Loss of Lime in some 

 Drainage Waters: A. W. Blaie and S. E. CoL- 



LISON. 



The paper describes soil investigations involving 

 the use of fertilizers in citrus culture in progress 

 at the Florida Agricultural Experiment Station. 

 A description of the large galvanized iron soil 

 tanks in use is given and rainfall records and 

 amount of drainage water collected from the 

 tanks for a period of three months are reported. 



The lime content of seven samplings of water 

 for the three months is given in parts per million 

 of water, and as pounds of calcium carbonate per 

 acre. 

 Some Poisons in Foods: H. E. Barnard. 



A general discussion of the various poisons 

 found in foods as preservatives and as they occur 

 in nature. 

 Determination of Dissolved Oxygen in Water: 



Geo. a. Sopee and Payne B. Parsons. 



This paper reports an accurate and rapid field 

 method for determining dissolved oxygen in water. 

 The oxygen is determined immediately after the 

 sample is taken. 

 The Determination of Arsenic in Insecticides: E. 



B. HOIiAND. 



The cooperation of the laboratory with the 

 entomologist in a study of arsenical insecticides 

 necessitated a great many determinations of ar- 

 senic. This led to a review of the literature on 

 the subject, careful consideration of the various 

 methods offered, and some improvements in the 

 iodine titration method as applied to the analyses 

 of arsenites and arsenates. 

 Purification of Insoluble Fatty Acids: E. B. 



Holland. 



Finding it impossible to purchase insoluble 

 fatty acids of a satisfactory quality, it became 

 necessary to undertake a study of various meth- 

 ods for their purification. 



The methods that seemed the best adapted for 

 the purpose were (a) distillation of the fatty 

 acids in vacuo, (6) crystallization from alcohol 

 and (c) distillation of the ethyl esters in vacuo, 

 and all were given extended trial. 



It was found that while saturated fatty acids 

 may be purified by distillation of either the acids 

 or their ethyl esters, the latter method is less 

 hazardous and much easier to manipulate, al- 

 though more steps are required. Crystallization 



