104 Dr. 0. Barus on the Aqueous Fusion of Glass. 



On referring to the explosion of ethylene with excess of 

 oxygen it is seen that C0 2 is not completely dissociated until 

 a temperature of 3500° C. is reached. In all cases the tem- 

 perature of explosion of cyanogen with excess of oxygen is 

 above this, and therefore C0 2 is never formed. 



The Pressure of Explosion. 

 The maximum pressure of explosion may be calculated with 

 the aid of the two formulae 



llY 2 

 and 



These two equations lead to the formula 

 /*V 2 C, ^ 



The pressure for an explosion of equal volumes of cyanogen 

 and oxygen calculated from this formula is 57 atmospheres. 

 Jones and Bower "* by breaking glass tubes obtain the value 

 58 atmospheres 



VII. The Aqueous Fusion of Glass, its Relation to Pressure 

 and Temperature. First Paper. By Carl Barus f. 



SOME time ago I published J a series of results due to the 

 action of hot water at 185° on glass, the water being- 

 kept liquid by pressure. It was shown that the water con- 

 tained in sealed capillary glass tubes increased in compressi- 

 bility while it steadily diminished in bulk, as described in the 

 subjoined summary of two consistent experiments with 

 different tubes. During the observations the column soon 

 became turbid, but it remained translucent enough to admit 

 of measurement. As the action at 185° proceeded, the 

 length of the thread of water decreased. This thread was 

 contained within the walls of the tube between two terminal 

 threads of mercury (the lower being movable and trans- 

 mitting pressure), and therefore decrease in the length of the 

 thread can only mean contraction of volume of the system of 

 glass and water in contact. The results are as follows : — 

 6 denoting the temperature of the capillary thread (main- 

 tained constant by a transparent vapour-bath) ; t the time 



* Journal of the Manchester Lit. and Phil. Soc. 1898. 



t Communicated by the Author. 



| Barus : American Journal of Science, xli. p. 110 (1891). 



