BRITISH ASSOCIATION FOR THE ADVANCEMKNT OF SCIENCE. 65 



dollatiphi Historise -^gypti Compendium.' The Arabic appellation of thunder is 

 somewhat different (raad), and has evidently originated from the supposition that 

 thunder is a trembling, or a state of agitation of the clouds ; or from its being a 

 cause of trembling. For the former of these two derivations we have the authority 

 of El-Bey dawee, in his ' Commentary on the Kur-an. ' Raa'ad' is a generic noun, and 

 ' Raa'adeh' is a noun of unity, meaning a single fish of the kind called ' Raa'ad.' 

 My reading of these words admits of no doubt, and is well known to Arabic 

 scholars." 



The modern Arabic name of the Nile electric fish thus does not justify the con- 

 clusion, that the Egyptians of past or present times believed that the shock of the 

 fish was the same in nature as a lightning-shock. A name exactly equivalent in 

 meaning is given, as Humboldt ineidently informs us, to the gymnotus as well as 

 the torpedo, by the South American Spaniards " who confound all electric fishes 

 under the name of tembladores, literally " tremblers," or "producers of trembling." 



At the present day the silurus of the Nile is sold in the markets of Cairo, and 

 used as food. 



The second point to be considered is the extent or generality of the practice of 

 using electrical fishes as shock-machines. In this, however, as in other matters, 

 it will be found that extension in space to a great degree corresponds to duration 

 in time. 



In ancient epochs the torpedo was probably employed medically on all the 

 shores of the Roman empire, including our own, which it visited, and traces of its 

 therapeutic use probably survive in some of them to the present day. I am un- 

 able, howevei*, to indicate any such traces more precise than^that the shock -giving 

 powers implied in its vernacular titles, such as the Maltese name of Haddayla, 

 a term whieh has reference to its benumbing powers; the French one. La Trem- 

 ble; and the English, specially expressive names cramp-^&h. and numb-^sh.. 



One modern people, however, makes use of the torpedo exactly as the ancients 

 did, though whether as a tradition from the Mediterranean electro-physicians, or 

 as an independent discovery, I have not the means of ascertaining. The Abyssin- 

 ians. Dr. Bradly tells us, employ the torpedo (I presume from the Red Sea,) in the 

 treatment of ferver. " The patient is first strapped to a table, and the numb-fish 

 then applied successively over every organ of the body : the operation is reported 

 to be both very painful and successful." 



Next to the torpedo, the gymnotus is the most famous among electrical fishes, 

 and it is by far the most powerful. The shock indeed, of a large gymnotus is so 

 severe, that no lover of heroic remedies, having one at command, need long for a 

 magneto-electric coil machine. Several species or varieties of the fish occur, as 

 Humboldt tells us, in the large rivers of South America, the Orinoco, the Amazon 

 and theMeta, besides frequenting their tributaries, and the smaller sti'eams of an 

 extensive bordering region. They have accordingly been familiar for centuries to 

 the Indians, who are constantly reminded of their presence, even in rivers too deep 

 to let them be caught or frequently seen, by the shocks which they feel when bath- 

 ing or swimming In tlie river. The shallower streams, also, and basins of stagnant 

 water, near the soui'ces of the Orinoco and elsewhere are, in this writer's words, 

 '■ filled with electrical eels," so that their shock -giving powers are forced upon the 

 attention of all visiting those districts ; and we cannot but feel curious to know 

 whether any therapeutic use has ever been made of living maebines so powerful. 

 VOL. III. E 



