Shock from Torpedo under various conditions 205 



sand, thoroughly soaked with salt water, to the depth of four inches, and 

 placed the torpedo in it, intirely covered with the sand, except the upper 

 part of its convex surface, and laid one hand on its electrical organs, and 

 the other on the wet sand about 16 inches from it. I felt a shock, but 

 rather weak; and as well as I could judge, as strong as if the battery had 

 been charged half as high, and the shock received in the usual way*. 



423] I next took two thick pieces of that sort of leather which is used 

 for the soles of shoes, about the size of the palm of my hand; and having 

 previously prepared them by steeping in salt water for a week, and then 

 pressing out as much of the water as would drain off easily, repeated the 

 experiment with these leathers placed under my hands. The shock was 

 weaker than before, and about as strong as if received in the usual way 

 with the battery charged one-third part as high. As it would have been 

 troublesome to have trod on the torpedo and sand, I chose this way of 

 trying the experiment. The pieces of leather were intended to represent 

 shoes, and in all probability the shoes of persons who walk much on the 

 wet sand will conduct electricity as well as these leathers. I think it 

 likely, therefore, that a person treading in this manner on a torpedo, even 

 with shoes on, but more so without, may be thrown down, without any 

 extraordinary exertion of the animal's force, considering how much the 

 effect of the shock would be aided by the surprise. 



424] One of the fishermen that Mr Walsh employed assured him, that 

 he always knew when he had a torpedo in his net, by the shocks he re- 

 ceived while the fish was at several feet distance; in particular, he said, 

 that in drawing in his nets with one of the largest in them, he received 

 a shock when the fish was at twelve feet distance, and two or three more 

 before he got it into his boat. His boat was afloat in -the water, and he 

 drew in the nets with both hands. It is likely, that the fisherman might 

 magnify the distance; but, I think, he may so far be believed, as that he 

 felt the shock before the torpedo was drawn out of water. This is the 

 most extraordinary instance I know of the power of the torpedo; but I 

 think seems not incompatible with the supposition of its being owing to 

 electricity; for there can be little doubt, but that some electricity would 

 pass through the net to the man's hands, and from thence through his 

 body and the bottom of the boat, which in all probability was thoroughly 

 soaked with water, and perhaps leaky, to the water under the boat: the 

 quantity of electric fluid, however, taking this circuit, would most likely 

 bear so small a proportion to the whole, that this effect cannot be ac- 

 counted for, without supposing the fish to exert at that time a surprizingly 

 greater force than what it usually does. 



425] Hitherto, I think, the effects of this artificial torpedo agree very 

 well with those of the natural one. I now proceed to consider the circum- 



* [Art. 608.] 



