150 REPORTS ON INVESTIGATIONS AND PROJECTS. 



while it is impossible to interpret them in terms of any other conception thus 

 far advanced. 



Having obtained such satisfactory results in aqueous solutions, we turned 

 our attention to solutions in non-aqueous solvents, working with methyl and 

 ethyl alcohols and acetone. To work with these solvents a special form of 

 cell was devised for holding the solutions, which could be assembled entirely 

 without cement. 



We worked with cobalt chloride in methyl alcohol, ethyl alcohol, and ace- 

 tone, and photographed the change in the absorption spectra produced by 

 the addition of varying amounts of water. In a similar manner work was 

 done with copper chloride in methyl alcohol, ethyl alcohol, and acetone; and 

 copper bromide was studied in methyl and ethyl alcohols. 



The bearing of the results obtained with non-aqueous solvents on the 

 present theory of hydrates is interesting. The fundamental interpretation 

 given to the widening of the absorption bands is that the vibrations of the 

 resonators were becoming less damped, which was due to the dehydration of 

 the vibrating systems. We should then expect that the absorption bands, 

 characteristic of a given colored salt, would be widest for the anhydrous 

 solutions, and would become narrower and narrower on the addition of more 

 and more water. The thirteen spectrograms obtained with non-aqueous 

 solutions all confirm this conclusion. The work in non-aqueous solvents is 

 then as confirmatory of the present hydrate conception as that in solutions 

 in water itself. 



The results of this investigation will soon be published in the form of a 

 monograph by the Carnegie Institution of Washington. 



Morse, H, Nv Johns Hopkins University, Baltimore, Maryland. Grant 

 No. 324. O71 the vieasurement of os?notic pressure. (For previous 

 reports see Year Book No. 2, p. xxx; Year Book No. 3, p. 108, and 

 Year Book No. 4, pp. 152-153.) $1,500. 



The work of the past year has consisted in (i) the construction of some- 

 what elaborate automatic devices for the maintenance of constant temper- 

 atures ; (2) the remeasurement of the osmotic pressure of cane-sugar ; and 

 (3) the measurement of the osmotic pressure of glucose. 



During the first series of measurements of the osmotic pressure of cane- 

 sugar great difficulty was experienced with certain ' ' thermometer effects ' ' 

 in the cells — that is, "temporary fluctuations of pressure which follow 

 changes of temperature, and are due to the expansion or contraction of the 

 liquids in the cell, and not to actual variations in osmotic pressure." It 

 was determined to eliminate these by constructing a bath in which very 

 nearly constant temperatures could be maintained automatically for any 

 desired length of time. The outcome of this part of the work was two 

 large water-baths — each sufficient for the accommodation of six cells, in 



