APEIL 17, 1903.] 



SCIENCE. 



623 



eessive layer was formed. The results ob- 

 tained agreed in a very satisfactory manner 

 witli the theory of diffusion and made it pos- 

 sible to determine the value of the 'metastable 

 solubility product.' The value found indi- 

 cated that at the limit of supersaturation the 

 solution contained 145 times as much silver 

 chromate as is required to form a precipitate 

 in the presence of the solid phase. 



A paper on the ' Eole of Thermo-Electro- 

 motive Forces in a Voltaic Cell' vcas pre- 

 sented by H. S. Carhart. The writer con- 

 sidered briefly the theory of a voltaic cell, so 

 far as relates to the properties dependent on 

 temperature, and showed that all these could 

 be completely explained by means of electro- 

 lytic thermoeleetromotive forces between a 

 metal and the liquid in contact with it. 

 Numerous experiments were described whose 

 results were in agreement with the theory. 



In a paper entitled ' A Simple Geometrical 

 Principle and its Possible Relation to a Gen- 

 eral Physical Theory,' Major J. Millis gave 

 an account of the possible modes by which a 

 number of equal spheres may be grouped. 

 It was shown that the grouping that is sym- 

 metrical and capable of indefinite extension by 

 the addition of more spheres is not the arrange- 

 ment that gives a minimum total volume. 

 The possible bearing of this fact upon molec- 

 ular theories was suggested. 



Dr. J. E. Benton described a ' Method of 

 Determining Internal Resistance, Applicable 

 to Rapid Polarizing Cells.' The method 

 is a modification of that of Beetz and gives 

 m.ore accurate results. It also has the ad- 

 vantage that it can be used for cells of small 

 electromotive force and resistance. 



The next meeting of the Physical Society 

 will be held on April 25. 



Ernest Merritt, 

 Secretary. 



NEBRASKA ACADEMY OF SCIENCE. . 



The thirteenth annual meeting of the 

 Nebraska Academy of Science was held in 

 Lincoln, Nebr., January 22 and 23, 1903. 

 President Charles Pordyce, Dean of Nebraska 

 Wesleyan University, presided. 



The following papers were read: 



' The Causes of Metamorphosis in Amhly- 

 sioma tigrinumf Dr. J. H. Powers. The 

 metamorphosis of Arnblystoma tigrinum is 

 not, as has been generally assumed, due to 

 enforced aerial respiration; neither is it 

 affected within wide limits by variations in 

 light or heat stimulus. The active causes are 

 variations in metabolism due to fluctuations 

 in food supply. Sudden checks in food supply 

 lead to immediate metamorphosis, slow and 

 constant food supply postpone metamorphosis 

 and prolong growth in larval stage. 



' Sand and Gravel Industry in Nebraska,' 

 Dr. G. E. Condra. 



' Summary of Study of fifty-seven Cases of 

 Phenomenal Chest Expansion in Nebraska 

 Schools,' Dr. W. W. Hastings. 



' The Diagnosis of Human Parasites,' Dr. 

 H. B. Ward. In this paper Dr. Ward dealt 

 especially with the necessity of more accurate 

 knowledge concerning the eggs of parasites, 

 and concerning the other evidence upon which 

 differential diagnoses might be made. 



'Absoi-ption of Starlight by our Atmos- 

 phere,' Professor G. D. Sweezey. 



'Wave Erosion on the Western Shore of 

 Lake Huron,' Dr. C. H. Gordon. 



'A Final Report of the Washings of the 

 Missouri River,' Professor H. B. Duncanson. 

 Professor Duncanson showed the regularity 

 of the shifting of the bed of the Missouri 

 River, and the laws governing the constant 

 gradual backward and forward movement of 

 the channel in the river valley. 



' An Old Channel of the Platte,' Dr. G. E. 

 Condra. Dr. Condra, by means of maps and 

 sketches, showed clearly the nature of the 

 broad valley passing from northwest to south- 

 east north of Wahoo, Nebr., which seems 

 clearly to have been a former Platte channel. 



' Common Sense and Computation,' Dr. E. 

 W. Davis. A paper devoted to showing errors 

 resulting from continued use of too many 

 decimals in computation. 



* On The Paramorphic Development of 

 Hornblende from Augite,' Dr. C. H. Gordon 

 (read by title). 



' On the Pyroxenites of the Greenville 



