1807. ^ET. 29.] PROFESSOR DAVY. 349 



that slightly act upon it ; and the volatile oils, the fat 

 oils ; but they all contain sufficient oxygen to render 

 the basis of potash alkaline, if it is exposed to them 

 for a sufficient time and in proper quantities, and that 

 more or less rapidly, according to the circumstances. 

 When naphtha or the oils are exposed to air they soon 

 alkalise the basis. Oxygen is absorbed from the air, 

 and a soap is formed, brown from the decomposition of 

 the compound fluid during the time of the alkalisation. 

 If air be excluded the process is a much longer time 

 in taking place ; no gas is emitted in the fixed oils or 

 in naphtha; but in the volatile oils hydrocarbonate 

 is produced in small quantities, and in all these cases 

 charcoal is deposited. In oil of turpentine the process 

 is more rapid than in any other oil I have tried, and 

 this oil contains either water or the elements of water, 

 and perhaps a larger proportion of oxygen to its 

 inflammable matter. 



' Nor ought we to be surprised that these substances 

 have never been produced in nature. Their strong 

 attraction for oxygen renders it impossible.' 



' The division into two poles : 



4 The basis of potash, by its strong attraction for 

 oxygen, decomposes all the metallic oxides which 

 I have exposed to it by a gentle heat. 



4 The oxides of lead it instantly acts upon, and the 

 metal is revived and alkali formed. In consequence 

 of this operation it cannot be preserved in tubes of 

 flint glass. 



' Are the bases of the fixed alkalies simple bodies ? I 

 perhaps shall be asked. 



