i320 Oil the Aerial Spider, 



Art. III. On the Aerial Spider, By John Murray, Esq. F.S.A. 

 RL.S. F.H.S. &c. 



Sir, 

 I FEEL gratified by the favourable review of my Experimen- 

 tal Researches in Natural History (published by George B. 

 .Whittaker, Ave Maria Lane), in your Second Number. As 

 far as I know, I have not ventured beyond the pale of sound 

 and sober reasoning, in the true spirit of inductive science. 



I have not presumed any thing in the shape of an opinion 

 on the origin of light. It issues from a cloud which conceals 

 its source. I have not attempted to penetrate its depth and 

 labyrinth. I may, however, be permitted to add that Canton's 

 phosphorus is merely composed of calcined shells, which a high 

 temperature illuminates. There is a considerable brilliance 

 excited, when the electric discharge is passed through this 

 substance, and I have found the following a very pretty expe- 

 riment: — Having strewn Canton's phosphorus (as it is called) 

 over the surface of mercury contained in a shallow basin, I 

 immerse into the fluid metal one of the wires of an extensive 

 galvanic battery, and bring the other polar wire in contact 

 with its surface ; at this moment the calcined particles become 

 beautifully luminous, and continue to glow for some time after 

 the positive and negative wires have been withdrawn. The 

 nature of the subject treated of in my little volume, necessarily 

 precluded a more full view of the nature and laws of light, and 

 its multifarious sources, and what I have introduced can be 

 only considered a very partial and superficial glance, as prefa- 

 tory to the topic treated of, namely " the light and luminous 

 matter of the glowworm." 



The object of this communication must, however, be chiefly 

 confined to the ascent and flight of the aerial spider. 

 • • Mr. Black wall's observations {Lin, Trans., vol. xv. part ii. 

 p. 449. et seq.) on this curious question are cited, in opposition 

 to my numerous and .varied experiments ; but I cannot admit 

 that they possess much consequence or force. It does not 

 appear that this author had seen an account of my experi- 

 mental researches on the ascent of the little aeronaut ; other- 

 wise, he might have hesitated in committing himself to the 

 Linnean Society, in the view he has endeavoured to sustain, 

 but which, however, I believe is not nevv. 



M. Gay Lussac having found that soap bubbles would 

 not ascend in a room, though their ascent is rapid in the open 

 air, unhesitatingly ascribes their ascent to warm currents ema- 

 nating from the surface of the ground ; rooted in this opinion, 



