456 



SCIENCE, 



[N. S. Vol. VII. No. 170. 



pearance, just as conditions (probably iden- 

 tical in character) have determined the 

 degeneration of other early nutritional 

 arrangements, i. e., the milk-teeth. We, 

 therefore, fall back upon the view that the 

 Metatheria and Eutheria are the divergent 

 branches of a common ancestral stock, 

 vrhich was not only diphyodont but also 

 placental." 



H. F. O. 



CUBBEyV NOTES OV ANTHBOPOLOQY. 

 THE TSIilSHIAN INDIANS. 



In 1S94: Count voq der Schulenberg pub- 

 lished in Germany a bulky quarto of nearly 

 four hundred pages on the language of the 

 Tsimshian Indians. Very few people, ei- 

 ther in Grermany or among ourselves, know 

 where the tribe, of some 3,000 souls, dwells. 

 Dr. G. A. Dorsey, therefore, did a good 

 piece of work when he wrote for the Ameriemi 

 Antiquarian (October, 1897, and reprint) a 

 few pages on their geographical location, 

 and added a map to make it clear. He re- 

 fers to their myths and names their vil- 

 lages, modern and ancient. He closes his 

 useful article with the common and fateful 

 forecast : "The fate of the Tsimshian, as 

 with his brother elsewhere on this conti- 

 nent, is to disappear." 



CAVE HUNTING IN YUCATAN. 



Under this title Mr. Henry C. Mercer 

 delivered a lecture before the Massachu- 

 setts Institute of Technology which has 

 been reprinted from the Technology Quar- 

 terly of December, 1897. It is a brief de- 

 scription of the work he did in Yucatan as 

 given at length in his volume, the ' Hill 

 Caves of Yucatan.' The lecture is illus- 

 trated with half a dozen very well printed 

 photographs, and sets forth clearly the re- 

 sults of his researches. 



Mr. Mercer thinks it necessary, toward 

 the close of his lecture, to defend the ex- 

 pedition from the charge of failure. No 

 one could have advanced such a charge 



who was capable of understanding the 

 value of the results he obtained. He is 

 quite right in vindicating for them an im- 

 portant position in the ancient history of 

 Mayan civilization ; though it would prob- 

 ably be going too far to say that they ex- 

 clude the possibility of finding the traces of 

 ' fossil man ' in Yucatan . 



D. G. Brinton. 



tlNIVEESITY OF PENNSYLVANIA. 



NOTES ON INOBGANia CSEMISTBY. 



Our knowledge of the carbids has been 

 decidedly increased by a new series of 

 experiments by Moissan described in the 

 Comptes Eendus. It has been known that 

 it is impossible to obtain carbids of sodium, 

 potassium or magnesium in the electric 

 furnace. These are readily formed, how- 

 ever, by heating the metal in acetylene gas. 

 Potassium, indeed, acts on acetylene at or- 

 dinary temperatures with the formation of 

 C^ HK, a compound intermediate between 

 potassium carbid and acetylene and which 

 yields acetylene with water. The corre- 

 sponding sodium compound C, HNa when 

 heated to nearly the softening point of Bo- 

 hemian glass decomposes into acetylene, 

 carbon and metallic sodium. Magnesium 

 carbid, similarly formed, decomposes in the 

 electric furnace into carbon and metallic 

 magnesium. The explanation of the im- 

 possibility of forming these carbids in the 

 electric furnace is that at so high a tem- 

 perature the carbid is completely decom- 

 posed. Indeed, in the manufacture of cal- 

 cium carbid, if the current is too strong (in 

 one experiment 60 volts and 1,200 amperes), 

 the calcium carbid formed is decomposed 

 into graphite and metallic calcium, the 

 latter distilling o&. Thus the stability of 

 the alkaline carbids is much less than that 

 of the alkaline earthy carbids. 



The fifth edition of the little brochure 

 ' Data concerning Platinum ' has just been 

 published by Baker & Co., of Newark, N. J. 



