704 REPORT—1899. 
standards may simultaneously appear, one atomic weight being referred to one, and’ 
another to another; the compiler being quite unconscious of the discrepancy. 
Tables of atomic weights which were good ten years ago reappear frequently in 
books of to-day, with no hint that any changes have occurred in any of the data. 
In order to remedy, at least in part, this unnecessary confusion in our funda- 
mental constants, the American Chemical Society in 1892 requested me to prepare 
an annual report upon atomic weights. Each year since I have submitted to the 
Society such a report (six in all), giving a summary of the determinations made, 
and a table of values brought down to the date of publication. So far as it went, 
the work seems to have been useful; but it did not go far enough, and it carried 
only the authority which might attach to the opinions of a single individual. More- 
criticism, more comparison of views among chemists, was evidently desirable ; and 
the movement in favour of international action seems to be a movement in the 
proper direction. 
In 1898 the subject was taken up independently by the German Chemical 
Society, which appointed a committee consisting of Landolt, Ostwald, and Seubert. 
This committee in due time reported a table of atomic weights, recommended the 
adoption of O= 16 as the standard of reference, and suggested that like committees 
might well be appointed by other societies for purposes of co-operation. Acting 
upon that suggestion, the American Chemical Society, at its last general meeting, 
appointed a committee consisting of F. W. Clarke, J. W. Mallet, E. W. Morley, 
T. W. Richards, and Edgar F. Smith; and that committee has already begun 
correspondence with the English and German organisations. A number of local 
societies in various parts of Europe have recommended the use of the table put forth 
by the German committee; but a full conference of all the parties at interest is yet 
to be held. Probably an effort will be made to discuss the atomic weight question: 
at the Congress of Chemists in Paris next year; but this proposition is so far only 
a matter under consideration. At all events, a general international committee 
might then be most readily brought together; and its recommendations would 
certainly carry much weight. 
What, now, could such a committee accomplish? In what directions should 
its influence be exerted? These are questions to be answered beforehand, for upon 
the answers the expediency of definite action must depend. Unless we have a 
reasonable expectation that something useful can be done, it is not worth while to: 
go any farther. 
Two lines of discussion for the proposed committee are self-evident: first, a 
_ discussion of the ultimate standard of reference, whether it shall beO=16 or H=1, 
and upon this question there are legitimate differences of opinion; secondly, a 
discussion of the existing data, in order to determine the most probable values for 
the atomic weights, and to get some insight into their relative accuracy. This 
involves the preparation of a table of atomic weights for practical use, in which 
some indication shall be given as to the trustworthiness of the individual values. 
Which figures have been well determined, and which need correction, should be 
clearly shown, and in that way future investigation would be stimulated. Such a 
table would call for revision from time to time, perhaps annually, and for this 
reason the committee should be made a permanent body, to act either by meeting” 
or by correspondence, according to circumstances. Only an international com- 
mittee could expect to have its findings generally accepted. 
Up to this point the work proposed for the committee has already been done, 
with more or less thoroughness, by the German committee, by Professor Richards, 
and by myself; so that the ground is pretty well cleared, and the field of action 
can be seen. But still more is desirable ; and just here, I believe, the task of the 
proposed committee may become most important. Having ascertained the wealx 
points in our system of atomic weights, the next thing to do is to have them 
strengthened; and to this end the combined influence of a body of trained experts 
might well be exerted. At present all research in this field of investigation is 
individual, and consequently the more obvious problems are simultaneously attacked 
by sometimes several independent workers, while other equally important questions 
are entirely neglected. A division of the field of labour, and co-operation in 
