88 Dr. Thomson’s Account of the [Frs. 
mity of thunder rods should be blunt. He exhibited a set of 
experiments in support of his opinion in the Pantheon, at which 
his present Majesty attended. The King adopted the opinion of 
Mr. Wilson, and altered in conformity with it the thunder rods 
attached to St. James’s Palace. But Mr. Wilson made no other 
convert : the dispute continued for a considerable time; but 
seems to have terminated in favour of pointed thunder rods. 
Dr. Ingenhousz in this paper gives his reasons for considering 
pointed rods as the most proper in conformity with the original 
proposal of Dr. Franklin; and his reasons appear perfectly 
satisfactory. It seems unnecessary to state them here, as I 
am not aware that any person at present supports the doctrine 
of Mr. Wilson. 
The fourth paper is a description of an electrical machine 
used by our author for various purposes. It consisted of a piece 
of strong silk suspended against the wall of a room, to which 
‘was attached a rubber of hare skin, or cat skin. He used it for 
charging small Leyden jars of a peculiar construction, which he 
describes. 
In the fifth paper he describes a small pocket electrical 
machine, intended for producing a spark sufficient fos firing an 
inflammable air pistol. 
In the sixth, he gives a description of the mode of burning 
camphor and phosphorus in oxygen gas, and describes the bril- 
hancy of these experiments with rapture. 
In the seventh, we have a contrivance for producing a vacuum 
by the property which charcoal has of absorbing air. It is need- 
less to observe that there seems little probability of any such 
substitute for an air pump being of much utility. 
In the eighth paper, we have a description of a method of 
lighting a candle by means of an electrophorus and an inflam- 
mable air lamp. The invention belongs to Strasburg. . At 
present we are in possession of better methods of accomplishing 
this object than those described in this paper. 
In the ninth paper, he describes his inflammable air pistol. 
This contrivance is too well known to require any details here. 
The tenth paper is a description of the mode which he employs 
to collect carburetted hydrogen gas from the bottom of stagnant 
water. 
The eleventh and twelfth papers are translations from the 
Transactions. 
The thirteenth paper is on oxygen gas. He procured it from. 
saltpetre, and he conceives that it would be a medicine of very 
great efficacy if it were given to patients ill of certain diseases, 
to be respired instead of common air. This opinion has not 
been verified by subsequent trials. 
The fourteenth paper is on the salubrity of the air above the 
sea compared with the air at dry land. It is a translation from 
the Transactions. 
