May 24, 1895.] 



SCIENCE. 



583 



impurities removable by sparking witli 

 oxygen in presence of caustic potash, ex- 

 liibits one, and only one, of the character- 

 istic bright red pair of ai'gon lines. This, 

 and other evidence of the same kind, ap- 

 pears to suggest that atmospheric argon 

 and helion have some common constit- 

 uent. 



Attention is drawn to the fact that on 

 subtracting IG (the common diflerence be- 

 tween the atomic weights of elements of the 

 first and second series) from 20, the ap- 

 proximate density of argon, the remainder 

 is 4, a number closely approximating to the 

 density of helion: or, if 32 be subtracted 

 from 40, the atomic weight of argon if it be 

 a monatomic gas, the remainder is 8, or 

 twice the density of helion, and its atomic 

 weight if it too is a monatomic gas. 



GRAVITY MEASUREMENTS. 



At a meeting of the Philosophical Society 

 of "Washington on March 16th Mr. G. K. 

 Gilbert discussed the gravity determinations 

 reported by Mr. G. E. Putnam, an account 

 of which is given elsewhere in the present 

 number of Science. Mr. Gilbert summa- 

 rizes his conclusions as follows: 



" The measurements of gravity appear 

 far more harmonious when the method of 

 reduction postulates isostacy than when it 

 postulates high rigidity. Nearly all the 

 local peculiarities of gravity admit of simple 

 and rational explanation on the theory that 

 the continent as a whole is approximately 

 isostatie, and that the interior plain is al- 

 most perfectly isostatie. Most of the devia- 

 ations from the normal arise ft-om excess of 

 matter and are associated with uplift. The 

 Appalachian and Kocky mountains and the 

 Wa.satch plateau all appear to be of the 

 nature of added loads, the whole mass above 

 the neighboring plains being rigidly upheld. 

 The Colorado plateau province seems to 

 have an excess of matter, and the Desert 

 Range province may also be overloaded. 



The fact that the six stations from Pike's 

 Peak to Salt Lake City, covering a distance 

 of 375 miles, show an average excess of 

 1,345 rock-feet indicates great<'r sustaining 

 power than is ordinarily ascribed to the 

 lithosphere by the advocates of isostacy. 

 It indicates also that the district used in 

 this discussion for estimating the height of 

 the mean plain is far too small ; even the 

 radius of 100 miles .selected by Mr. Putnam 

 may not be large enough."' 



CiEXERAL. 



In a paper read before the Paris Academy 

 on April 29th MM. Hericourt and Ch. 

 Richet announce that they have applied 

 the method of injecting serum in the treat- 

 ment of cancer. Two patients only have 

 undergone this treatment, one of whom is 

 said to have been completely cured. 



Rev. J. M. Seely-e, president of Amherst 

 College from 1877 to 18it0, died at Amherst 

 on May 12th, at the age of .seventy. For 

 nineteen years before his election to the 

 presidency' he filled the chair of mental and 

 moral philosophy and retained this chair 

 until his death. His original contributions 

 to philosophy were not important, but he 

 exercised great influence as an educator 

 and teacher. 



We learn that Deputy Surgeon-General 

 John S. Billings, of the army, has requested 

 that he be placed on the retired list ; and 

 that in October that distinguished oflicer 

 will leave the Army Medical Museum, of 

 which he is curator, and the Library of the 

 Surgeon-General's Office, of which he is 

 librarian, and these magnificent institutions, 

 that have been made what they are largely 

 by his ability and zeal, will know him no 

 longer. Before the date he has selected for 

 his retirement he hopes to complete his 

 work on the final volume of the Index 

 Catalogue. In seeking official retirement 

 Dr. Billings does not propose to give up 

 work, as he has accepted the chair of 



