26 



SCIENCE 



[Vol, LVI, No. 1436 



umes moleeular coneentrations being 0.0072, 

 0.0048, 0.0072. The basia for the determination 

 of the best solution was the dry weight of tops. 

 To five pots Titamines extracted from yeast was 

 added. This increased the growth of the plants 

 quite noticeably. 



A dietary study of some state institutions: 

 E. H. S. Bailey. This is a study of the dietary 

 of each of the groups at the different institutions 

 under the care of the Kansas State Board of 

 Administration, where shelter, food and clothing 

 are provided. The calculations are made from a 

 complete report of all the food used for a series 

 of months, sometimes during the entire year. The 

 proteins, fata and carbohydrates and the calories 

 per day per capita are worked out for each insti- 

 tution according to a commonly accepted method. 

 The number of inmates at these institutions being 

 large, and the conditions varied, an excellent 

 opportunity is afforded for a comparison and for 

 constructive criticism on the quantity, variety 

 and cost of the food furnished. 



Studies on the electropure process of treating 

 milk: Floyd W. Robison. This paper gives a 

 rfisum^ of previous work on the treatment of milk 

 by electricity and gives in detail the results of 

 the author's studies on the improved apparatus. 

 The apparatus is described in detail and its essen- 

 tial characteristics emphasized. Results of 

 studies on bacterial reduction; keeping qualities 

 of the treated milk; effect on cream line, etc., are 

 given and include a very thoroughly conducted 

 experiment on the effect of the process on bacteria 

 of tuberculosis in milk. The great value of the 

 process is pointed out and certain automatic con- 

 trol features dwelt upon. The application of the 

 electric current and the method of preventing the 

 electrodes from becoming hot, thus eliminating 

 any heated taste, are important features in the 

 light of their effect on the treated milk. The 

 process produces a milk free from pathogenic 

 organisms and with a phenomenal bacterial reduc- 

 tion. The keeping quality of the treated milk is 

 excellent and its commercial values otherwise 

 greatly enhanced. The apparatus is illustrated. 



The role of manganese in plants: J. S. 

 McHaegue. The purpose of this investigation 

 was to determine if manganese has any definite 

 function to perform in plant economy. The meth- 

 od of attack has been the preparation of plant 

 nutrient compounds and quartz sand, free from 

 manganese, and the growing of plants in different 

 portions of nutrient solutions or sand cultures 

 from which manganese was withheld and in an- 



other equal number of portions of these media to 

 which manganese was added. All the plants wer« 

 grown until those that received manganese showed 

 signs of fructification and a few to maturity. The 

 plants from which manganese was withheld made 

 a normal growth for about six weeks only. There- 

 after they became chlorotic and the young leaves 

 and buds died back and the plants made no 

 further growth of any consequence, whereas the 

 plants to which manganese was available grew in 

 a normal way and fructified where the plants were 

 grown to that state of maturity. The author con- 

 cludes that manganese is necessary in the plant 

 economj' and that, therefore, eleven elements are 

 necessary for the normal growth of autotrophic 

 plants, whereas it has been taught previously that 

 only ten are necessary. 



The absorption of water by soil colloids: W. 0. 

 Robinson. A method is given for determining 

 the amount of water absorbed by the air-dried 

 colloid under specified conditions. It was found 

 that the water absorbed by purified colloids from 

 thirty-five different soils was nearly a constant, 

 the average being .298 grams of water absorbed 

 per gram of colloid. A tentative method is pro- 

 posed for determining the amount of colloid in a 

 soil by finding the amount of water absorbed 

 and dividing this figure by .298. The assump- 

 tions involved are discussed. 

 Division or Physical and Inorganic Chemistet 



S. E. Sheppard, chairman 



E. E. Wilson, secretary 

 Theory of the structure and polymorphism of 

 silica: Roeekt B. Sosman. There exists a wide 

 variety of experimental data on the forms of 

 silica, and particularly on quartz, which have 

 never been assembled and explained on the basis 

 of a single consistent set of hypotheses as to the 

 ultimate structure of this substance. This paper 

 attempts to provide such a set of hypotheses, 

 based upon the general knowledge already gained 

 concerning the structure of matter in general and 

 silica in particular. It is believed that the silica 

 atom-triplet maintains a certain degree of indi- 

 viduality in its amorphous and crystalline states 

 as well as in its compounds, and the freedom of 

 its oxygen atoms to change their positions with 

 respect to the silicons is restricted. The triplets 

 are assumed to assemble into chains or threads in 

 the liquid and glassy states, and a thread struc- 

 ture persists in the crystalline states (cristobalite, 

 tridymite, chalcedony, quartz). The high-low or 

 alpha-beta inversions in all the forms are thought 

 to be due to the same underlying change, namely, 



