CHEMISTRY — RICHARDS. 20I 



(3) A new form of platinum-lined steel bomb has been constructed, by 

 which the specific volume, compressibility, and vapor-pressure of water can 

 be determined between 310° and its critical temperature. Preliminary meas- 

 urements of these quantities have already been successfully made; and the 

 apparatus and measuring instruments have been accurately calibrated. The 

 new form of bomb is also adapted to the measurement of the conductivity 

 of solutions at these high temperatures. 



(4) The research having for its object a study of the hydration of the ions 

 of salts in aqueous solution by means of electrical transference measurements 

 in the presence of a non-migrating solute, which has been in progress for 

 over three years, has been brought to a conclusion, and a paper prepared de- 

 scribing the results. This investigation has conclusively demonstrated that 

 the ions of the alkali elements are hydrated ; and that the hydration increases 

 in the order, potassium, sodium, lithium, while the equivalent conductance of 

 these ions increases in the inverse order ; thus affording an explanation of the 

 long-known fact that the larger the atomic weight of the ion, the more rapid 

 its rate of migration. 



Richards, Theodore W., Harvard University, Cambridge, Massachusetts. 

 Grant No. 414. Investigation of the values of atomic zveights and other 

 fundamental physico-chemical constants. (For previous reports see 

 Year Books Nos. 2, 3, 4, 5, and 6.) $2,500. 



Eight researches were conducted under the direction of Professor Rich- 

 ards with the support of grants from the Institution, as follows : 



(i) An investigation of the atomic weights of lithium, chlorine, and silver, 

 carried on with the assistance of Mr. H. H. Willard. Of this investigation 

 the first part (concerning the atomic weight of lithium as obtained from the 

 analysis of its chloride) is almost finished, and shows without doubt that the 

 atomic weight of lithium is 6.94 (Ag= 107.88), or quite a per cent lower 

 than the value found by Stas. The reason for the error of Stas has been dis- 

 covered. The second part of the investigation, involving the analysis of lith- 

 ium perchlorate, is well advanced ; and many precautions which are necessary 

 for exact results have been discovered and tested. It has been found that 

 with proper treatment lithium perchlorate is exceedingly well fitted for the 

 purpose of deciding the existing controversy as to the true atomic weight of 

 silver with reference to oxygen. Mr. Willard, having obtained further leave 

 of absence (through the courtesy of the authorities of the University of Mich- 

 igan, where he holds an instructorship), will continue the work during the 

 coming winter. 



(2) An investigation concerning the atomic weights of nitrogen and sil- 

 ver, carried on with the assistance of Mr. F. B. Cofiin. This work involves 

 the analysis of ammonium bromide and supplements the work on ammonium 



