Intelligence and Miscellaneous Articles. Ill 



conducting power of the pelvis muscles, which if cut off weaken too 

 much the general effect, must also be deducted, as well as the anta- 

 gonist force of the extensor muscles. The necessity for all these re- 

 ductions makes the problem a very complex one. M. Matteucci be- 

 lieves, however, that he has done sufficient to establish the general 

 result, that a far greater amount of work can be realized from the con- 

 sumption of a given quantity of zinc acting on the limbs of a recently- 

 killed animal, than when the same quantity is employed to work an 

 inorganic machine. 



NEW APPLICATION OF ELFXTRICITY TO SURGERY. 



A novel application of electricity has been described by Mr. Smee 

 at his lectures on Surgery, delivered at the Aldersgate Street School 

 of Medicine. He states that needles and other steel instruments are 

 frequently impacted in the human body, and do irretrievable mischief, 

 but may be detected by rendering them magnetic. The following 

 extracts will sufficiently explain the modus operandi : — 



" You are all acquainted with the curious condition which steel 

 assumes under certain circumstances, whereby it evinces properties 

 which are called magnetic ; you know, moreover, that like magnetic 

 poles repel, and opposite attract each other. You have, therefore, but 

 to render a piece of enclosed steel a magnet, and you will be able not 

 only to ascertain its presence, but to determine by its polarity its 

 general direction ; and by the amount of magnetism it evinces, you 

 may even infer its probable bulk, 



"When you suspect the presence of a piece of needle, or other 

 steel instrument, you must subject the suspected part to a treatment 

 calculated to render the needle magnetic ; and there are two prin- 

 cipal methods by which this object may be effected ; — the first, by 

 transmitting a galvanic current, at right angles, to the suspected 

 part ; the second, by placing a large magnet near the part affected, 

 so that the object may be magnetized by induction. You may ac- 

 complish the first end, by taking a copper wire, covered with cotton, 

 or still better with silk (in fact, you may employ the covered wire as 

 generally used for the formation of electro -magnets), and wind it 

 round the parts suspected to contain steel, several times, so that the 

 same current may act at right angles, many times, upon the piece of 

 steel ; you may then take a galvanic battery (one of my little tumbler 

 batteries will amply suffice), and connect one end of the wire to the 

 zinc, the other to the platinized silver. The current might be con- 

 tinued for half an hour, or more, when the steel would become mag- 

 netized, and thereby give strong indications of its presence. 



" For my own part, I should use the second plan, or the plan of 

 magnetizing by induction, to render the needle magnetic. For this 

 purpose I have employed a temporary electro-magnet, Avhich I mag- 

 netized by the voltaic battery, and you will find, that by keeping the 

 part affected as close as possible to the instrument for about half an 

 hour, you will sufficiently obtain the desired object. 



" The electro-magnet might be made of the horse-shoe form, if we 

 knew the direction of the object ; but in that case we should not re- 



