EVOLUTION OF GASES FROM HOMOGENEOUS LIQUIDS. 



2G5 



Effect of Glass Dust. 



A quantity of glass dust was obtained by breaking RUPERT'S drops, and sifting the 

 finely divided glass through a sieve. 

 A mixture was made up as follows : 



300 c.c. sulphuric acid, 

 130 water, 



into which was filtered slowly 85 c.c. of water containing 10 grams of sodium 

 formate. Two portions, each of 1 75 c.c., of this mixture were taken, placed in two 

 flasks, which were heated in a water bath side by side. 



Mean temperature 79'5. The observations are divided into sets of 50 c.c. each ; 

 the volumes collected in the two tubes were read simultaneously. 



From the above results it is evident that the rate of evolution of gas from the 

 mixture with the glass dust is greater than that from the mixture without the 

 glass ; the difference between these rates diminishes as the change proceeds, owing, 

 partly, at least, to the greater diminution of mass in the former case than in the 



MDCCCLXXXVni. A. J M 



