TRANSACTIONS OF THE SKCTIONS. 55 



nation of these gases is very rapidly achieved, and if mixed in the 

 proper proportion, they are converted, usually with the phjenomena 

 of ignition, altogether into water. It is also well known, and was 

 first noticed by Dr. Turner, that if into an atmosphere of oxygen and 

 hydrogen, mixed in the ratio necessary for forming water, certain other 

 inflammable gases, such as carbonic oxide and olefiant gas be introduced, 

 the combination of the oxygen and hydrogen is, if not altogether sus- 

 pended, at least materially interrupted. Tliis is what Dr. Henry de- 

 nominates gaseous interference. The cause of this remarkable effect 

 has, at different times, attracted the attention of eminent chemists. 

 Dr. Turner has ascribed it to the soiling of the platinum by the inter- 

 fering gas ; Dr. Faraday to some peculiar condition induced in the metal ; 

 while Dr. Heniy himself, at a period long prior to the present, con- 

 ceived it to arise from the fact of carbonic oxide and olefiant gas having 

 a stronger affinity than hydrogen for oxygen gas. In his present paper. 

 Dr. Henry investigated the entire question. The prominent facts and 

 inferences appeared to be that carbonic oxide retards and limits, but 

 does not altogether prevent the action of platinum on the usual explo- 

 sive mixture, and the same may be said of olefiant gas. The interfering 

 power, however, of the former is vastly greater than that of the latter, 

 their ratio being represented by the numbers 1 8 and 1 . In the case of 

 carbonic oxide, carbonic acid is always produced, the amount depend- 

 ing on the form of the platinum employed, the quantity of the inter- 

 fering gas, and the temperature at which the experiment is conducted ; 

 and, as a general rule, it may be laid down, that the intei-fering in- 

 fluence of the gas bears an inverse relation to the energy with which 

 the platinum acts, and the degree of heat — conditions, however, which 

 may be considered as identical. The diminution, and even disappear- 

 ance, of interference at high temperatures. Dr. Henry attributes to a 

 relative augmentation of the affinity of hydrogen for oxygen, an hy- 

 pothesis indeed established by other and independent facts. 



That Dr. Henry's theory of gaseous interference is the true one, 

 he infers from the general fact of no gases exercising any such in- 

 fluence but those which have an affinity for oxygen ; and that it is 

 strictly true, at least in the case of carbonic oxide, there can be no 

 question, seeing that some of the oxygen is actually employed in the 

 production of carbonic acid. 



In the course of the paper several other interesting facts, of a col- 

 lateral description, were stated, and, amongst others, that platinum 

 causes, though slowly, the combination of a mixture of oxygen and 

 carbonic oxide, but that the process is facilitated by the introduction 

 into the jar of a little caustic potash. This latter circumstance he 

 attributed to the removal of the carbonic acid by the potash as fast as 

 it was produced. 



