Proceedings of the Polytechnic Association. 995 



Eemedy for "Wakefulness. 



Prof. W. A. Hammond, of Bellevue College Hospital, New York, . 

 gives, in 2 he Medical Record^ an interesting paper on " The Thera- 

 peutics of "Wakefulness," which contains the following passage : " But 

 of all the sleep-producing agents at our disposal,'the bromide of potas- 

 sium is most deserving of the name of hyphotic. I have never seen 

 it fail when given in sufficient quantity. A healthy adult may take 

 from twenty to thirty grains three times a day ; the latter is not too 

 large when it is needed at all. Sometimes it produces, among its 

 other effects, great weakness in the legs, and a staggering gait, strongly 

 resembling that of a person intoxicated with alcohol. In fact, 1 know 

 a gentleman who, while under the influence of this drug, was twice 

 arrested in our streets for drunkenness. Bromide of potassium occa- 

 sionally produces great lowness of spirit and a disposition to cry. • It 

 should be administered very much diluted. It may- be conveniently 

 prescribed, one ounce to four ounces of water ; a drachm dose of this 

 to be given in at least half a tumblerful of water. 



A remedy which I have used recently, especially in cases of nervous 

 excitement, where a sedative seemed indicated, is sumbul. This is a 

 plant of the same family as valerian. I have used it in conjunction 

 Mnth bromide of potassium, in epilepsy, with the result, I think, of 

 increasing the effect of the latter. The dose of the fluid extract 

 (Neergaard's) is from twenty drops to a drachm three times a day. 



Cannon Shot and Armor. 



Recent experiments by the ordnance department, made at Shoe- 

 buryness, England, have shown that the force of a cannon shot in 

 foot pounds is the weight of the projectile multiplied by the square 

 of the velocit}^ divided by twice gravity, equal to sixtyfour. For 

 example, a Eodman projectile of twelve inches diameter, and weigh- 

 ing 620 pounds, striking at one-third of a mile distance, equals in 

 round numbers 15,000,000 foot pounds. This efi'eot is the same 

 witliin certain limits Avith heavy shot with low velocity, and with 

 high shot with high velocity, producing the same force of impact; 

 but with shot of different diameters the force must be proportionate 

 to the diameter, as in ordinary punching. The resistance of armor 

 plates varies nearly as the square of their thickness. This applies 

 only to solid plates, and not to a series of plates bolted together. A 

 four-inch solid plate could not be penetrated, while a six-inch lamin- 

 ated plate was easily penetrated by cannon shot of the same force. 



