480 



SCIENCE 



[N. S. Vol. XXX. No. 771 



thus occur in ijairs, wliicli is not a fact. This 

 theory of spiral nebulse is therefore directly 

 contradicted by the most obvious phenomena 

 of the heavens. 



4. In the same number of the Astrophysical 

 Journal it is announced that Saturn's ninth 

 satellite, Phmhe, can not now escape from the 

 control of the planet, so, " conversely, it has 

 never come under Saturn's control from a 

 remote distance." Of course this interpreta- 

 tion of the use of Jacobi's integral is wholly 

 unjustifiable. Under the secular action of a 

 resisting medium such a capture is perfectly 

 possible, and it has actually taken place, not 

 only for the retrograde satellites, but for all 

 of them. 



5. The planets and satellites could have been 

 formed in but one or more of the three follow- 

 ing possible ways, and in no others whatsoever : 

 {a) Detached from their central masses by 

 acceleration of rotation, as imagined by La- 

 place, (b) Captured from the outer parts of 

 a nebula devoid of hydrostatic pressure and 

 thus added on from without, as announced by 

 the writer in A. N., 4308. (c) Formed right 

 where they now revolve by the agglomeration 

 of cosmical dust. 



Now the possibility (o) is forever excluded 

 by what I have called Babinet's criterion 

 (4. N., 4308) ; while (c) will not be seriously 

 considered by any one of ordinary understand- 

 ing. This leaves (h) as the only possible 

 mode of formation. 



6. Not content, however, with proving by the 

 logical process of exclusion that the planets 

 and satellites were captured, I have since de- 

 veloped a rigorous proof, based on a correct 

 interpretation of Jacobi's integral under the 

 physical conditions existing in actual nature, 

 of just how the capture of satellites comes 

 about. A series of papers on this subject is 

 just now appearing in the Astronomische 

 Nachrichten, No. 4341-42, 4343, etc. 



Y. It is thus proved that the planets were 

 captured by the sun and have gradually neared 

 that central mass under the secular action of 

 a resisting medium. This cause and no other 

 has given the orbits their round form. It is 

 proved also that the satellites likewise were 

 captured by their several planets. If Moulton 



and Chamberlin have reached any but nega- 

 tive results, I have not yet seen them, and I 

 shall look forward with interest to their pub- 

 lication. Since naturally a thing has occurred 

 in but one way, it is evident that there are in 

 general an infinite number of ways in which 

 ii did not occur. Such negative results may 

 be as numerous as the sands of the sea, or as 

 the points in space; but they will no more 

 nourish our minds than empty space will feed 

 our bodies. I submit that protest against 

 such vacant results is certainly justifiable. 

 T. J. J. See 

 U. S. Naval Observatory, 

 Mare Island, Califorkia, 

 August 2, 1909 



" DM " AND " lUM " ENDINGS 



The Editoe of Science: A subject which 

 has interested me for some time is the existing 

 lack of uniformity in the ending of the names 

 of some chemical elements. In view of the 

 fact that nomenclature is under discussion at 

 the present time, possibly some remarks on the 

 above subject may not seem presumptuous. 



Some of my spare moments have been em- 

 ployed in trying to find if there were any con- 

 clusive reasons why five of the elements 

 should have the endings they possess rather 

 than endings in conformity with the majority 

 of their brothers in the list of elements. The 

 five I refer to are glucinum, lanthanum, 

 molybdenum, platinum and tantalum. 



Using Roscoe and Schorlemmer as author- 

 ity, the number of " um " and " ium " elements 

 is forty-seven. Five of these (the above men- 

 tioned) have " i " absent in the ending. Of 

 the latter the Oxford English Dictionary and 

 the Century Dictionary are authorities for 

 spelling glucinum, lanthanum, tantalum both 

 with and without the " i." Therefore there re- 

 main but two of the elements which as far as 

 I have been able to discover are never spelled 

 with the " ium " ending. In fact the leading 

 text-books on chemistry and writers on sci- 

 entific subjects spell all five elements with the 

 " um " ending. So we are justified in believ- 

 ing it to be common usage to leave out the 

 " i " in the spelling of the five elements under 

 consideration. 



