481 



amber, when moderately heated, were attracted as acids to the positive 

 side ; but when these bodies were ignited so as to admit a dense 

 smoky flame, the. carbonaceous, matter was drawn, Eke that of other 

 resinous bodies and camphor, to the negative ball. 



The majority of these instances, says the author, serve well to 

 illustrate the inherent electrical states of different species of matter, 

 and give a further proof of the identity of common and voltaic 

 electricity, and especially the attraction of the fumes of the phos- 

 phoric and benzoic acids to one side, and of the fumes produced by 

 the combustion of potassium and camphor to the other. 



But there are some phenomena that did not turn out as might 

 have been expected. The combustion of carburetted hydrogen, for 

 instance, gives rise to the production of water and of carbonic acid ; 

 but its flame is attracted by the negative surface. It is conceived, 

 however, that this direction may be given to the flame by its carbo- 

 naceous contents rather than by the products of its combustion. 



Mr. Brande is of opinion that these experiments may suggest a 

 fair explanation of the phenomena presented by those bodies that 

 are termed unipolar by Mr. Erman, because when connected with 

 one or other extremity of the voltaic battery, they transmit the in- 

 fluence of only one species of electricity. The flame, for instance, 

 of oil or of wax must be considered as consisting chiefly of these 

 bodies in a state of vapour; and as their natural electricity is positive, 

 they will have no tendency to destroy that of a positive pole with 

 which they are connected, and the gold leaves of an electrometer 

 will continue to diverge ; but when they are applied to a negative 

 pole, their inherent positive electricity will neutralize that of the 

 battery to which they are united, and the gold leaves will in con- 

 sequence collapse. 



An Account of some new Experiments on the fluoric Compounds; with 

 some Observations on other Objects of Chemical Inquiry. By Sir 

 H. Davy, LL.D. F.R.S. V.P.R.I. Read February 13, 1814. 

 [Phil Trans. 1814, p. 62.] 



Since the date of those attempts of the author to decompose 

 fluorine, of which an account has already been printed in our 

 Transactions, and from which he inferred that pure liquid fluoric 

 acid consisted of hydrogen united to a base which he had not then 

 been able to procure in a separate form, but which is detached from 

 the hydrogen by various metals, he has made many experiments that 

 in his opinion tend to confirm this idea, though all his attempts to 

 effect the actual decomposition have been unsuccessful. 



Fluate of lead, which, according to the author's view of its consti- 

 tution, consists of lead united to the peculiar fluoric principle, is not 

 decomposed by dry ammonia; but by liquid ammonia it yields oxide 

 of lead, in consequence of the decomposition of water which gives 

 oxygen to the lead, and hydrogen to the acid which now enters into 

 the composition of fluate of ammonia. 



