378 Evaporation and Dissociation. Chlorophyll. [June 21, 



VIII. " Evaporation and Dissociation. Part VIII. A Study of 

 the Thermal Properties of Propyl Alcohol." By William 

 Ramsay, Ph.D., F.R.S., and Sydney Young, D.Sc. Re- 

 ceived June 14, 1888. 



(Abstract.) 



In continuation of our investigations of the thermal properties of 

 pure liquids, we have now determined the vapour- pressures, vapour- 

 densities, and expansion in the liquid and gaseous states of propyl 

 alcohol, and from these results we have calculated the heats of vapo- 

 risation at definite temperatures. The compressibility of the liquid 

 has also been measured. The range of temperature is from 5° to 

 280° C, and the range of pressure from 5 mm. to 56,000 mm. 



The memoir contains an account of the purification of the propyl 

 alcohol ; determinations of its specific gravity at 0°, and at 10° "72 ; 

 and of the constants mentioned above. 



The approximate critical temperature of propyl alcohol is 263 0, 7; 

 the approximate critical pressure is 38,120 mm., and the approximate 

 volume of one gram is 3*6 c.c. The first two of these constants must 

 be very nearly correct ; the third cannot be determined with the same 

 degree of precision. 



The memoir is accompanied by plates, showing the relations of 

 volume, temperature, and pressure in a graphic form. 



IX. < f Contributions to the Chemistry of Chlorophyll. No. III." 

 By Edward Sohunck, F.R.S. Received June 19, 1888. 



(Abstract.) 



This paper is a continuation of the previous ones on the same 

 subject. In it the author gives an account of the action of alkalis on 

 phyllocyanin so far as regards the first stage of the process, and of 

 the products thereby formed. Phyllocyanin when acted upon by 

 alkalis yields in the first instance a well -crystallised substance of a 

 peacock- or steel-blue colour, to which he gives the name of Phyllo- 

 taonin. He describes its properties and those of some of its com- 

 pounds. When hydrochloric acid gas in excess is passed through a 

 solution of chlorophyll in alcoholic soda, a compound crystallising in 

 lustrous purple needles is formed, which seems to be the ethyl ether 

 of phyllota,onin. By substituting methylic for ethylic alcohol a very 

 similar compound is obtained, which the author considers to be the 

 corresponding methyl ether. Though these compounds readily yield 

 phyllotaonin by saponification with alcoholic potash or soda, the 

 author did not succeed in reproducing them by the combined action 

 of alcohol and hydrochloric acid on phyllotaonin. 



