DETECTION OF NEEDLES. 67 



must have had frequent opportunities of observing cases, in 

 which portions of steel are introduced into the body, in the 

 shape of needles, or as points of cutting instruments : frequently 

 such foreign bodies remain unnoticed, and without producing 

 any mischief for some lengthened time, and ultimately, perhaps, 

 find their way to the surface; a small abscess is formed, and 

 they are thus discharged. But although this is a frequent ter- 

 mination of such accidents, unfortunately it is not the only 

 one ; it occasionally happens that they become lodged in a 

 joint; the affected part will swell, suppurate, and discharge; 

 ulceration of the cartilages and osseous tissue supervenes ; and 

 the mischief is generally so great as to produce anchylosis. 

 Such a case occurring to Mr. Smee, induced him to turn his 

 attention to the subject. " Some time since," writes Mr. Smee,* 

 " I had a case under my care, where a small portion of a needle 

 was introduced into one of the joints of the finger, but of which 

 no indication existed, beyond the effects which might have been 

 expected from the presence of a foreign body. The exact spot 

 of its insertion was unknown, and indeed, it was equally uncer- 

 tain whether it was inserted or not. Subsequently, the joint 

 swelled, suppurated, and discharged, and a small piece of needle 

 was found firmly impacted in the bone. Now a very small 

 piece of foreign matter is capable of producing such disastrous 

 results, and on having weighed the piece discharged in this 

 case, I found that it scarcely amounted to the seventh of a 

 grain. Now it occurred to my mind that, had I known that the 

 needle was actually present, and could have demonstrated the 

 exact spot, I might have possibly averted the present incon- 

 venience of a stiff joint to the unfortunate sufferer; and after 

 having carefully considered the matter, a plan suggested itself 

 to my mind for the detection of needles in future cases." 



The plan by which Mr. Smee proposes to remedy such acci- 

 dents, depends upon the well-known fact, that steel may, in 

 many ways, be rendered magnetic ; thus, by the approximation 

 of a powerful magnet, by the circulation of a current of electri- 



* Reported in the Medical Times. 



