CHEMISTRY — MORSE. 1 8/ 



and ammonium chloride. Some interesting and important results were 

 obtained in connection with the influence of temperature on the effect of one 

 salt on the dissociation of another salt with a common ion. 



The spectroscopic investigation which is now in progress is a continuation 

 of the work of Jones and Uhler. It has had to do with an enlargement of the 

 spectrograph so as to include still longer wave-lengths than were recorded in 

 the earlier work. A study has been made of various photographic films, to 

 ascertain which would give the most satisfactory records over the greatest 

 range of wave-lengths. Various sources of illumination have been investi- 

 gated to see which would give the best results over the widest range. One 

 source has been found which apparently fulfills the desired conditions very 

 satisfactorily. 



The absorption spectra of solutions of such substances as cobalt chloride, 

 cobalt bromide, copper chloride, and copper bromide, in the alcohols, acetone, 

 etc., keeping the total amount of the colored salt constant, and varying the 

 concentration by the addition of more or less of the solvent or solvents, are 

 being photographed. 



The same line of work will also be extended to solutions of such sub- 

 stances as ferric chloride, ferric citrate, ferric sulphocyanate, cobalt bromide, 

 cobalt acetate, cobalt sulphocyanate, copper acetate, chromic acid, and the 

 like, in water as the solvent, using as wide a range of dilution as is practical. 



The absorption spectra of a number of the above-named substances are 

 also being studied in pure non-aqueous solvents, and in such solvents to which 

 varying amounts of water are added. 



The effect of rise in temperature on the absorption spectra of solutions 

 of colored salts, to which already some attention has been given, will be 

 studied much more thoroughly as this investigation proceeds. 



The absorption spectra of solutions of different concentrations of a given 

 salt, containing the same number of colored particles in the path of the 

 beam of light, are also being photographed. 



Morse, H. N., Johns Hopkins University, Baltimore, Maryland. Grant No. 

 412. On the measurement of osmotic pressure. (For previous reports 

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

 4, pp. 152, 153, and Year Book No. 5, pp. 150-153.) $1,800. 



The work completed during the past year under grants from the Carnegie 

 Institution of Washington, has been described in a series of four papers. 

 These appeared in the April, May, June, and August numbers of the Ameri- 

 can Chemical Journal for 1907, under the following titles: 



The osmotic pressure and the depression of the freezing-point of solutions of glucose. 

 The osmotic pressure of cane-sugar solutions in the vicinity of the freezing-point of 



water. 

 The osmotic pressure of glucose solutions in the vicinity of the freezing-point of water. 



The osmotic pressure of cane-sugar sohitions in the vicinity of 5°. 



