140 



Dr. J. Monckman. The Specific 



gas took place even after the sulphur had been boiled at the ordinary 

 pressure of the atmosphere, and also after a considerable evolution at 

 150° when, apparently, all gas was driven away, a second one occurred 

 on raising the temperature. 



One or two precautions are necessary in order to get good results. 

 The sulphur is a bad conductor of heat, and therefore one part of it 

 near the flame may be many degrees above another in the interior. 

 The vapour from the hotter bursts through the cooler liquid and 

 rising into the space C causes a higher temperature to be registered 

 than the true one. By reducing the flame, and by surrounding the 

 portion B with a conductor such as mercury for temperatures below 

 350°, the heat can be regulated and spread until this is avoided. 



T|he curve is drawn from data furnished by experiments at various 

 temperatures up to 340° only, one temperature being taken above that, 



