August 17, 1906.] 



SCIENCE. 



197 



tory by Mr. E. B. Hart and myself satis- 

 factory evidence was produced to show that 

 casein can and does combine with acids to 

 form insoluble casein salts. An- attempt 

 was made to settle the quantitative side of 

 the question by suspending free casein in 

 a given amount of dilute acid of known 

 strength, filtering and determining the 

 amount of acid left uncombined. This 

 method was found to be inadequate. It 

 then occurred to the writer that results 

 might be obtained by suspending free casein 

 in dilute acid and then testing the filtrate 

 for changes of electrical conductivity. 

 This work is being done largely by Mr. 

 Donald D. Van Slyke. 



The conductivity method shows that the 

 base-free casein forms an insoluble com- 

 pound with dilute hydrochloric acid, which 

 slowly combines with more acid forming 

 a soluble compound. This soluble com- 

 pound forms more readily with more con- 

 centrated acid and is unstable, being readily 

 decomposed by bases with precipitation of 

 a compound probably pure casein. Fur- 

 ther the conductivity method shows that 

 the amount of acid combined with casein is 

 considerably in excess of that found by 

 the method first used and that the low re- 

 sults are accounted for by the formation 

 of this soluble compound. 



The work is still unfinished and many 

 other phases will be studied. 



Movement of Water and Solutions in SoUs: 

 F. K. Cameron and J. M. Bell. 

 It has been pointed out in Bulletin 30, 



Bureau of Soils, that the movement of 



water in capillary media is described by the 



empirical formula, 



y" = -£■<. 



Further experiments show that in case of 

 the movement of water through a capillary 

 tube n is equal to 2. A theoretical deduc- 

 tion of this formula has been given. 



Relation of Sodium to Potassium in Soil 

 and Solution Cultures: J. F. Bbeazeale. 

 (By title.) 



The Distribution of Soluble Bodies between 

 Water and Soils, or other Finely-divided 

 Solids: F. K. Cameron and H. E. 

 Patten. 



It has been shown that the rate of absorp- 

 tion generally follows the law expressed by 

 the equation 



which is the equation describing a reaction 

 of the first order. The distribution of sub- 

 stances, both organic and inorganic, be- 

 tween a soil or other absorbing material 

 and the solvent was studied, and it was 

 found in a majority of cases that the curves 

 were of a logarithmic character, which ap- 

 pears to be expressed by the empirical 

 formula, 



y 



log 



C—y 



K,. 



Several cases were found, however, which 

 were better expressed by a linear equation. 

 It was shown that the soils and other ab- 

 sorbing media have a maximum saturation 

 capacity, C in the above formula, which 

 has an important significance from an 

 agricultural point of view. 



Abnormal Transpiration in relation to 

 Growth in Wheat under Certain Condi- 

 tio')is: Oswald Schreiner and Charles 

 A. Jensen. (By title.) 



Superphosphates: F. K. Cameron and J. 



M. Bell. 



In the four-component system — lime, sul- 

 phuric acid, phosphoric acid, water, which 

 are the essential constituents of superphos- 

 phates—five stable solids have been found 

 at 25°, viz., monoealcium phosphate, 

 dicalcium phosphate, anhydrite, gypsum 

 and a series of solid solutions in phosphoric 

 acid and lime. The inversion points and 



