August 31, 1S83.] 



SCIENCE. 



287 



the plate with another. Later I got some fairly good 

 results in articuUtion by using a small diaphriigm 

 with all the conditions as nearly right as possible; 

 and, having a current of sufficient electro-motive 

 force, I could actually understand words produced on 

 the end of my finger. 



President Howland. — Wliat is the difference be- 

 tween that and Edison's motorplione ? 



Mr. Gk.vv. — In Edison's motorphone, when the 

 current was thrown on, there was a decrease of fric- 

 tion; there was chemical action taking place on the 

 surface. In this case there is none, and there is an 

 increase of friction when the current is on: perhaps 

 ' current ' is a bad word to use. 



President Kowla.nd. — The principle is the same. 



Mr. Gray. — One is a chemical action, which causes 

 the friction to be less at the moment of charge. In 

 this case, however, this is purely static contact, and 

 increases the friction in the same manner that the 

 plates are thrown together when they are charged 

 in this telephone. Ami the motion, of course, or 

 sound, is produced by a letting-go of the linger from 

 the plate, and not by actual vibration, in the same 



sense that it takes place between the two plates in 

 this receiver of Professor Dolbear. 



President Rowland. —You attribute it to attrac- 

 tion? 



Mr. Gray. — Yes: my experiments seem to prove 

 that; I presume, because there was adhesion, there 

 was an increase of friction during the time of the 

 charge and the letling-go, when the circuit was open. 

 There was really no circuit except when the charge 

 was taken off. 



Sec. F. E. NiPHER. — In regard to the case of 

 which Professor Dolbear spoke, when it might be 

 supposed that electricity does actually pa's from the 

 line into the ground, it seems to me that that fact, so 

 far as it did exist, would be prejudicial to the action of 

 the instruments; that what we want to bring about 

 is not a current, but as great a difference of potential 

 as possible, between the plates. 



Iiist of other papers. 

 The following additional paper was read in this 

 section: — An extension of tlie theorem of the virial 

 to rotary oscillation, by U. T. Eddy. 



PROCEEDINGS OF SECTION C— CHEMISTRY. 



Report of the comnuttee on indexing the 

 literature of chemical elements. 



The undersigned, a committee appointed at the 

 Montreal meeting of the American association for 

 the advancement of science, '"to devise and inau- 

 gurate a plan for the proper indexing of the litera- 

 ture of the chemical elements," respectfully submit 

 the following report. 



The menil)Orshave conferred with each other orally 

 and by correspondence. Several plans have been 

 suggested, and their merits discussed. Three meth- 

 ods of collecting material for the indexes may be 

 named : — 



1°. Revising the Catalogue of scientific papers 

 published by the Royal Society (8 vols. 4to). 



2°. Inilexing special journals by different individ- 

 uals, and collating the matter. 



3°. The independent plan, whereby each chemist 

 indexes all the journals available to him with refer- 

 ence to a given element, in which he is presumably 

 especially interested. 



Each of these schemes is open to objections, and 

 has its difficulties. The first would necessitate an 

 jenormous amount of clerical labor, for which volun- 

 teers would scarcely bo secured; besides, data previ- 

 ous to ISUO could not be obtained from this catalogue. 



The second involves, also, securing a large num- 

 ber of self-sacrificing volunteers; and both plans 

 would require a Ta<t amount of editorial work on the 

 part of this committee. 



The third plan seems, to a majority of the commit- 

 tee, the only feasible one at present. On the inde- 

 pendent plan, seven indexes have already been com- 

 piled. The best arrangement of material has also 



been considered; and here again a threefold prob- 

 lem occurs : — 



1. Chronologically. 



2. Alphabetically, by authors, 

 .i. Topically. 



The committee do not venture to dictate to inde- 

 pendent workers, but recommend the chronological 

 arrangement, with the understanding that a topical 

 index accompany each monograph. 



The best channel of publication has also been con- 

 sidered' by the committee. All the indexes hitherto 

 published have been printed in the annals of the 

 New-York academy of sciences; and the academy 

 has generously offered, through its officers, to con- 

 tinue its good work. The Smithsonian institution 

 further agrees to distribute, free of expense, all 

 circulars and documents in furtherance of this un- 

 dertaking; an offer which is of greatest importance, 

 and for which this committee expresses sincere 

 thanks. 



Since the appointment of the committee, Mr. 

 Webb's index to the literature of electrolysis has 

 been published in the annals of the New-York 

 academy of sciences; and several chemists have 

 expressed a willingness to co-operate in the proposed 

 undertaking. Prof. R. B. Warder of Cincinnati has 

 promised an index to the literature of the velocity 

 of chemical reactions; and Dr. Henry I^cffmann of 

 Philadelphia proposes to index the important element 

 arsenic. 



Your committee present to the association this 

 brief report of progress, and respectfully desire to 

 be contiimcd. 



II. C. Boi.TOjf, Chairman; Ira Remsen; F. W. 

 Clabke; A. R. Leeds; A. A. Julien. 



