B8 Mr. D. Waldie's Experimental Researches 



tied, through which a slender platinum or iron wire could be 

 passed to try the temperature of different parts of the flame, 

 and to the other was fixed a bladder in order to allow of ex- 

 pansion. The flask was filled by being immersed in a trough 

 of water ; the water was then displaced by inserting one of the 

 flexible tubes into one of the sockets, and causing gas to flow 

 into it from a connected gas-holder, the water escaping by 

 the other socket ; the tube was then removed, corks inserted 

 in the sockets, and the flask placed on a retort stand, with its 

 mouth downwards and the bladder hanging flaccid : the tube 

 was then replaced in the socket so as to supply more gas if 

 necessary. Now when the flask was filled with one of the 

 common supporters, such as oxygen, and one of the common 

 combustible gases was to be burnt in it, the method requires 

 no explanation. When again the oxygen was to be burnt in 

 hydrogen the cork was removed from the socket, and the gas 

 set fire to, being made to flow gently from the flask, in order 

 to prevent the combustion from getting inwards ; the oxygen 

 then being made to flow with a proper degree of force from 

 a small brass jet fixed on the end of another flexible tube, 

 communicating with another gas-holder containing oxygen, 

 was passed steadily through the burning hydrogen into the 

 flask, and the end of the flexible tube pushed home into the 

 socket ; the hydrogen burning outside the flask was now ex- 

 tinguished, and the oxygen found burning within. 



When again the gas was not confinable in a common gas- 

 holder with water, such as nitrous acid vapour, it was pre- 

 pared in a wide-mouthed flask ; and when this was believed 

 to be full, a jet of hydrogen burning from a brass nozzle 

 fixed to the turned-up extremity of a glass tube connected 

 with a flexible tube was let down into it : or, for instance 

 with chlorine, a jar was filled with this gas over the water- 

 trough, and a jet let down as before, a tin plate being fixed to 

 the tube so as to cover the jar and allow the jet to descend 

 to near the bottom. If again these gases were to be burnt the 

 materials were placed in a small flask, to which was fixed a 

 tube having a brass piece to fit the socket of the flask, and a 

 jet placed on its extremity. 



By means of such apparatus oxygen was made to burn in 

 atmospheres of hydrogen, olefiant gas, coal gas, sulphuretted 

 hydrogen and carbonic oxide; nitrous oxide was burnt in 

 hydrogen and coal gas; nitrous acid vapour in hydrogen; 

 chlorine in hydrogen, and mixtures of these with nitrogen or 

 carbonic acid, common air for instance, in the same gases. 



By these experiments, oxygen, atmospheric air, nitrous 

 oxide, nitrous acid and chlorine are shown to be not only 



