December 8, 1922.] 



SCIENCE 



667 



tion, parallax, radial velocity and notes concerning 

 other points oi interest. 



The status of research on the perturbations of 

 Viinor planets with special reference to its ulti- 

 mate significance: Armin O. Leusohner. 



The structure of the Jura Mountains in France. 

 Lantern: Emanuel de Makgerie (introduced 

 by J. F. Kemp). 



Recently discovered evidence hearing on the age 

 of the Sierra Nevada. Lantern: John C. Mer- 

 RiMAN, E. W. Ghanet and C. Stock. 



American jade and its archeological i earing. 

 Lantern: Henry S. Washington. Microscopic 

 study of many jade objeots from Cliiclien Itza, 

 Copan and localities in Mexico shows thait the 

 material consists of a jade-like pyroxene and 

 albite in different proportions; varjdng from 

 pure pyroxene to nearly pure albite. The pyrox- 

 ene is composed of jadeite and diopside, the eoni- 

 biuation forming a hitherto unrecognized mem- 

 ber of the pyroxene group. Many chemical 

 analyses have been made, ajid these, as well as 

 the microscopic ,tliin sections, show that the albite 

 is soluble in the daopside-jadeite up to a cer- 

 tain amount, beyond which it crystallizes out sep- 

 arately. In chemical and mineral chai-acters the 

 Middle American jades differ markedly from 

 those of Burma and Tibet, the chief sources of 

 Chinese jade. These differences, the occurrence 

 of a complete series of the rocks, and the orig- 

 inal pebble form of many of the American jade 

 objects, indicate that the material of the Mexi- 

 -ean and Central American artifacts is of Ameri- 

 can, and not of Asiatic, provenance; thus being 

 adverse to the theory of southeastern Asiatic 

 origin for Middle American races and culture. 

 This American jade has not yet beeoi found in 

 place, but it is probable that it comes from 

 toward the Pacific coast, and two centers of pro- 

 duction are suggested as prolbable, Oaxaca-Guer- 

 rero in Mexico and Guaitemala in Central 

 America. 



Browned coral reefs of the Liu Kin, Islands, 

 Johnson (introduced by J. F. Kemp). 



A genetic description of some New England- 

 Acadian shorelines. Lantern: Douglas W. 

 Johnson (introduced by J. P. Kemp). 



A tentative geological column for central Mon- 

 golia: Charles P. Berkey (introduced by J. F. 

 Kemp). 



Xenoliths in the Stoiiy CreeJc granite, Connecti- 

 cut: James F. Kemp. 



A chemical investigation of two typical en- 

 zymes : pancreatic and malt amylases : H. C. 

 Sherman. This paper reraews briefly some of 



the results obtained in an investigation carried 

 out during recent years with the aid of grants 

 from the Carnegie Institution of Washington, and 

 describes unpublished experiments which furnish 

 a new line of evidence thajt these enzymes, in 

 their chemical nature, either are proteins or con- 

 tain proteins as essential constituents. While 

 ailike in this respect, these two starch-splitting 

 enzymes differ markedly in some of their prop- 

 enties and are undoubtedly different substances. 

 Some of the chief points of resemblance and of 

 difference are briefly summarized and the prob- 

 lem as to the conclusiveness of the evidence re- 

 garding the chemdeal nature of these enzymes is 

 considered. 



The hydration of sodium monometaphosphate 

 to orthophosphate in varying concentrations of 

 hydrogen ion: H. T. Beans and S. J. Kiehl. 

 The preparation of sodium monometaphosphate; 

 method of following the hydration; experimental 

 data; formation of pj'rophosphate as an inter- 

 mediate product; discussion of results. 



Saturated Bredig gold sols: H. T. Beans and 

 L. B. Miller. Briefly summarized the paper will 

 present the results of the eontiniiation of our 

 w;ork on the study of the influence of electrolytes 

 on , the composition and behavior of gold sols 

 made by the Bredig method. We have found 

 that a very definite quantitaltive relationship 

 exists between the maximum amount of gold 

 which can be dispersed by the Bredig method, and 

 the character and concentration of the electrolyte 

 preseiit. The paper will, therefore, consist in a 

 demonstration of this relationship with curves and 

 data which are in support of the conclusions. 



Experimental studies on the hydrogen electrode: 

 H. T. Beans and L. P. Hammett. A study of 

 the practical application of the hydrogen elec- 

 trode and of theoretical questions involved has 

 shown that the hydrogen electrode must function 

 not only as an inert electrode, but as a catalyst 

 for the hydrogen ion reaction. Comparison of 

 various methods for producing the necessary ac- 

 tivity is of interest from the general point of 

 platinum catalysis, and indicates the interesting 

 problem of the potential difference between active 

 and inactive electrodes. These results, together 

 with the results of the study of the effect of 

 oxygen upon the electrode have led to a specifiica- 

 tion of the necessary conditions for precise meas- 

 urements in buffered solutions, and investigation 

 of the difficulties inherent in the application of 

 the electrode to unbuifered solutions has led to the 

 determination of the reasons underlying these dif- 

 ficulties, and to a now tjTpe of electrode which 



