BIOLOGY — CHEMISTRY. 325 



better because of the relatively high frequency of the unusual types of 

 exceptions (primary and "equational"). 



A new type of chromosome-disturbance, known as ''transposition," 

 is being investigated. A piece of a second chromosome has apparently 

 been broken off and then become attached to a third chromosome. 

 Other special problems have also been studied on the Drosophila 

 material. Dr. 0. L. Mohr, of the University of Christiania, has exam- 

 ined certain questions, the most important being a modification of a 

 region of the sex chromosome that is responsible for the character 

 known as Notch. Miss M. B. Stark has continued her work (at the 

 University of Indiana) on hereditary tumor. Mr. S. R. Safir has prac- 

 tically completed the cytological study of the XO male. Dr. J. F. 

 Nonidez has begun an examination of the normal process of fertilization 

 in D. melanogaster and in species crosses. The combined results of all 

 the work done on Drosophila is the basis of a book now ready for pub- 

 hcation, entitled "The Physical Basis of Heredity." 



CHEMISTRY. 



Noyes, Arthur A., Throop College of Technology, Pasadena, California 

 Researches upon (1) the properties of solutions in relation to the ionic 

 theory; (2) the determination of the atomic structure of crystalline sub- 

 stances by X-rays. (For previous reports see Year Books Nos. 2-17.) 



Several investigations have been conducted, with the aid of elec- 

 tromotive force measurements, on solutions of largely ionized elec- 

 trolytes. The free energy at various concentrations of potassium 

 hydroxid has been determined by Mr. Ming Chow. Mr. Chow has 

 also completed a study of cells of the form H2, HCl(ci)+KCl(c2), 

 Hg2Cl2+Hg, in which the total concentration (C1+C2) was kept con- 

 stant. His results lead to the conclusion that, so long as this condition 

 prevails, the respective ions behave as perfectly normal solutes. 



Mr. J. A. Beattie has nearly completed an investigation of the free 

 energy of lithium chloride at various concentrations. The measure- 

 ments were made on cells with and without hquid junctions, and 

 accurate values for the transference-numbers of the salt have been 

 obtained by combination of the results. 



Work has also been continued on the determination of oxidation 

 and reduction potentials. Mr. C. E. Ruby has studied the equilibrium 

 conditions of the reaction 3K2Mn04+2H20 = 2KMn04+Mn02 4- 

 4K0H. Relations between the three higher oxidation stages of man- 

 ganese have been derived from the results. 



The researches on the determination of crystal structure by X-ray 

 analysis has been continued by Dr. D. A. Maclnnes and Mr. F. C. 

 Hoyt. Besides the modifications of the Bragg apparatus previously 

 referred to, consisting in the addition of a reference crystal and an 



