POPULAR MISCELLANY, 



281 



brations as a remedy for neuralgia. The 

 publication of M. Boudet de Paris was ear- 

 liest in time; but Dr. Mortimer-Granville 

 has been prosecuting researches on the sub- 

 ject for several years, while he intended to 

 withhold the results from the public until 

 the efficacy of the new remedy could be fully 

 established. The publication of M. Boudet 

 de Paris has, however, made it necessary for 

 him to describe his own views and experi- 

 ments, so far as he has gone, though he still 

 considers them unperfected. His attention 

 was drawn to the subject by the success of 

 applications of ice in alleviating neuralgic 

 pains in labor. Having persuaded himself 

 that if the nerve affected in such pains could 

 be strongly impressed, so as to change its 

 state of irritation, the pain would cease, he 

 tried the effect of tapping over the fifth 

 nerve in ordinary facial neuralgia. The re- 

 sults were "very remarkable." He then 

 devised an instrument, a percuteur^ which 

 would give a known number of blows in a 

 second. The operations of this instrument 

 were remarkable, although they are not yet 

 considered decisive as to its efficacy. In 

 numerous instances, pain was arrested by 

 its application, and did not return. ^Yhen 

 applied over a healthy nerve, which was so 

 situated as to be thrown readily into me- 

 chanical vibration, it produced a sensation 

 like that caused by the passage of a weak, 

 interrupted current of electricity, changing, 

 when the action was prolonged, into a sen- 

 sation of tingling, then of numbness, and 

 finally to some twitching of the superficial 

 mu%cles. A nervous headache, or migraine, 

 could be produced by an application to the 

 frontal ridges or the margins of the orbit. 

 In some instances, when pain existed, the 

 sensation was aggravated by the augmented 

 state of vibration into which the nerve was 

 thrown through the shaking of the adjacent 

 tissues. It is noteworthy that a compara- 

 tively high number of vibrations per second 

 seems to relieve a dull, aching, or grinding 

 pain, while an acutely pitched and quick 

 pain is most frequently arrested by a slower 

 movement of the instrument. This is in 

 harmony with the theory that the pain is 

 the result of abnormal nervous vibration, 

 and that the operation of the percuteur is 

 to arrest those motions by opposing counter 

 and interfering vibrations to them. M. Bou- 



det de Paris relates in his paper that, by the 

 aid of a large tuning-fork and sounding- 

 board, he caused hemianesthesia to disap- 

 pear; provoked contractions in hysterical 

 patients at the Salpetriere as rapidly as 

 with the magnet or electricity ; and sub- 

 dued the pains of an ataxic. With a modi- 

 fied apparatus he was able to produce local 

 analgesia, often anaesthesia, in a healthy 

 man, or a sensation of approaching vertigo, 

 with a desire for sleep. An attack of mi- 

 graine could be cut short by the application. 

 Neuralgia, especially of the fifth nerve, dis- 

 appeared after a few minutes' application of 

 the instrument; but it was more difficult 

 to get good results with the deeper-seated 

 nerves. Both gentlemen suggest that the 

 action of metallo-therapy, or of metallic ap- 

 plications, is best explained on the theory 

 of vibrations. 



Some Facts about Explosions. Mr. Cor- 

 nelius Walford has lately attempted to col- 

 late the statistics of explosions, as a help 

 to ascertaining their causes and the means 

 of avoiding them. A large increase in such 

 disasters, which has been remarked in mod- 

 ern times, is easily accounted for when we 

 remember that we deal with explosive ma- 

 terials and machinery vastly more than our 

 ancestors did. The returns of the deaths 

 from explosions in England and Wales, dur- 

 ing twenty-two of the years between 1852 

 and 1879, give a total of 6,814, or 309 a 

 year, of which 187 a year were ascribed to 

 explosions of fire-damp, 37 to those of boil- 

 ers, and 70 to those of chemicals, including 

 gunpowder. Assuming, as the insurance 

 companies do, that one hundred persons 

 are hurt by such accidents where one is 

 killed, a proportion which is not confirmed 

 by the figures that follow, we have an 

 annual average of 30,900 persons injured 

 by explosions in England and Wales. Xo 

 means exist of ascertaining the amount of 

 property destroyed. Explosions of chem- 

 icals are increasing in frequency and va- 

 riety of character as new processes are intro- 

 duced in the arts. Remarkable instances 

 of these occurred at Gateshead in 1854, 

 when, during a fire, nitrate of soda and 

 sulphur, neither of which would explode 

 alone or in simple combinations, exploded 

 terribly when water was brought to bear 



