466 



SCIENCE. 



[N. S. Vol. XV. No. 377. 



compreliension of the cranial nerves is the doc- 

 trine of nerve components as developed (chiefly 

 by American students) during- the past decade, 

 a doctrine which apparently very few neurol- 

 ogists in Europe have yet really comprehended. 

 The fifty pages of this work devoted to the 

 peripheral nervous system will serve as an ad- 

 mirable and not too technical introduction to 

 this important subject, and will doubtless has- 

 ten the day when it will filter down into the 

 text-books. C. Judson Herrick. 



SOCIETIES AND ACADEMIES. 



RESEAKCH CLUB OF THE UNIVERSITY OF 

 MICHIGAN. 



Since last reported this Club has held two 

 meetings, one on December 18, 1901, the other 

 on January 8, 1902. 



At the former meeting. Dr. A. E. Cushny 

 read a paper on 'Eenal Secretion and Diure- 

 sis,' in which he first discussed the two chief 

 theories on the subject and then attempted to 

 apply them to the explanation of the diuresis 

 induced by the intravenous injection of saline 

 solutions. When a mixture of sulphate and 

 chloride of sodium in equal parts is injected, 

 the chloride of the urine first exceeds the sul- 

 phate in amount, while later the' reverse is the 

 case. This is most simply explained by the 

 reabsorption of chloride in the renal tubules, 

 which take up this salt much more readily 

 than the sulphate. When the absorption is 

 accelerated by partial closure of the ureter, 

 which increases the pressure in the tubules, 

 the chloride of the urine diminishes much 

 more than the sulphate. The behavior of the 

 chloride and sulphate of the urine tlius con- 

 firms Ludwig's theory that the renal tubules 

 are absorptive rather than secretory organs. 

 In the discussion which followed, it was inti- 

 mated by the reader of the paper that there 

 were grounds to believe that the secretory 

 cells of the renal capsule are unable to dis- 

 criminate between sulphate and chloride and 

 that the relative amounts of these in the 

 glomerular fluid is determined by their rela- 

 tive proportion in the plasma of the blood. 



At the conclusion of Dr. Cushny's paper, 

 Professor Henry C. Adams spoke on 'Trusts.' 

 Giving at first the older classification of busi- 



ness and commercial organizations as limited 

 by profitable administration, the speaker de- 

 voted his time to the enquiry as to whether 

 conditions have so changed as to make pos- 

 sible the profitable combination into one or- 

 ganization of two or more formerly econom- 

 ically distinct classes of business. 



At the meeting of January 8, Dr. Guthe 

 spoke on the action of the coherer with special 

 reference to the investigations which he lias 

 published in the Annalen der Physik, 4, p. 762, 

 1901, and in the Physical Review, 12, p. 245, 

 1901. 



After a short description of the single con- 

 tact coherer used by him and an explanation 

 of the so-called decohesion, he calculated how 

 near the metallic surfaces must be brought 

 together in order to produce coherer action. 

 The work of Earhart on sparking distances 

 leads to the conclusion that the insulating 

 layer can only have a thickness of a fraction 

 of the wave-length of sodium light, while the 

 distance corresponding to the critical voltages 

 of different metals, as found by him, must be 

 of molecular dimensions. Thus the thickness 

 of the air film, if the original high resistance 

 is really due to such a fihn, can be only a 

 very small fraction of its normal value. But 

 it seems unnecessary to assume the presence 

 of a layer of air between the surfaces in all 

 cases in which coherence takes place. The 

 decrease in resistance or actual metallic con- 

 tact between the coherer particles. Dr. Guthe 

 believed to be due mainly to the welding to- 

 gether of the metals at the point of contact 

 by the heat produced when even a minute 

 quantity of electricity passes through an ex- 

 tremely small area of high resistance. 



Dr. Guthe was followed by Dr. S. J. 

 Holmes, who spoke on 'The Habits of Am- 

 phipods,' detailing many interesting actions 

 in their life history. Portions of the results 

 obtained by Dr. Holmes have been published 

 in the Biological Bulletin and in the Ameri- 

 can Journal of Physiology. The later obser- 

 vations have appeared in abstract in Science 

 in the report of the Chicago meeting of the 

 Morphological Society. 



Frederick C. Newcombe, 



Secretary. 



