Febkuaky 3, 1899.] 



SCIENCE. 



185 



NOTES ON INORGANIC CHEMISTRY. 



Seveeal months ago M. and Mme. Curie 

 separated from pitch blende a strongly radio- 

 active substance for which they proposed 

 the name polonium. In the Compies Eendus 

 for December 26th, in conjunction with 

 M. B6mont, they describe another suppos- 

 edly new element in pitch blende for which 

 they propose the name radium, while the 

 elementary character of polonium is con- 

 firmed. Polonium in its chemical nature seems 

 to resemble bismuth, while radium is analytic- 

 ally indistinguishable from barium. Indeed, it 

 would appear, especially as the spectrum of 

 the new substance is apparently identical with 

 that of barium, except one line, that in their 

 samples radium is present only in small pro- 

 portion and as an impurity in barium. The 

 claim that it is a new element is based upon the 

 radio-activity of the substance. Barium is not 

 radio-active, while the substance obtained from 

 pitch blende is extremely radio-active. By so- 

 lution of the chlorid in water and precipitation 

 with alcohol the substance may be fractioned 

 until the chlorid is 200 times more active than 

 uranium. In the spectrum of this substance 

 Demarcy finds a line whose wave-length is 

 3814.8, and which is not due to any known 

 substance. The further the chlorid is frac- 

 tioned the stronger this line appears. Au 

 atomic weight determination showed a varia- 

 tion from that of barium only within the limits 

 of experimental error. 



In the January number of the American Chem- 

 ical Journal the work of E. C. Franklin and C. 

 A. Kraus on liquid ammonia (already noticed 

 in this Journal) is continued. Since many in- 

 organic salts are soluble in liquid ammonia, 

 the probability of metathetic reactions, analo- 

 gous to those in water, would be great. Such 

 the authors find actually take place. Using 

 the nitrates of sixteen metals, and the sulfid, 

 chlorid, bromid, iodid, chromate and borate of 

 ammonium as precipitant, it is found that those 

 salts which are insoluble in ammonia are readily 

 precipitated. The reactions with ammonium 

 sulfid present the most interest, as the com- 

 pounds formed differ in many cases at least 

 from those formed in aqueous solution, as is 



evidenced by their color ; for example, that with 

 cobalt is pink, with nickel and with cadmium, 

 white. The cobalt and the cadmium compound 

 assume the normal color of the sulfid on adding 

 water. These seem to be complex compounds, 

 as the precipitate from magnesium nitrate with 

 ammonium sulfld was examined and found to 

 correspond best to the formula 2MgS, (NH,)2S, 

 xNHg, where x is 9 or 10. 



Considering in a second paper some of the 

 properties in liquid ammonia the authors show 

 its close relation to water. As a solvent for 

 salts it is only surpassed by water ; it closely 

 approaches water in its power of dissociating 

 electrolytes ; indeed, some salts conduct elec- 

 tricity better in ammonia solution than in 

 aqueous solution ; in many compounds it plays 

 the same part as water of crystallization ; its 

 specific heat is as great as that of water and its 

 molecular elevation constant is lower than that 

 of any other substance yet measured. As a 

 solvent it differs from water in not dissolving 

 the sulfates and sulfites, the alkaline carbonates, 

 phosphates and oxalates, and hydroxids. In its 

 solvent power for organic substances it comes 

 nearer alcohol than water. The solid ammonia 

 is not, like water, specifically lighter than the 

 liquid, nor does it exhibit a maximum density 

 above its melting point. Altogether, the inves- 

 tigations which Professor Franklin is carrying 

 out on liquid ammonia promise to enrich our 

 chemical knowledge in no small degree. 



J. L. H. 



CURRENT NOTES ON ANTHROPOLOGY. 



BAD FORM IN ANTHROPOLOGICAL WRITINGS. 



In a note to one of his recent articles Dr. S. 

 R. Steiumetz criticises, with just severity, two 

 faults conspicuous in some writers on anthro- 

 pology (though surely not peculiar to works in 

 this branch). The one is the appropriation, 

 without any or sufficient acknowledgment, of 

 the work of others. This rhay arise from inad- 

 equate preparation, an ignorance of what others 

 have written, or a half- knowledge of it, as well 

 as from deliberate intent. 



The second fault is constant self-repetition 

 and self- reference. I can name a writer whose 

 references to his own writings exceed those to 



