PROCEEDINGS OP THE POLYTECHNIC ASSOCIATION. 493 



dog" of a celebrated singei- wliom I knew would moan bitterly and g'ive 

 sig'ns of violent suffering' the instant tli:it his mistress clianted a chromatic 

 gamut. A certain chord produces on my sense of hearing the same effect 

 as the heliotrope on iny sense of smell and the pineapple on my sense of 

 taste. Rachel's voice delighted the ear by its ring before one had time to 

 seize- the sense of what was said, or appreciate the purity of h(!r diction. 



"We may affirm, then, that musical sound, rhythmical or not, agitates 

 the whi)le physical economy — quickens the pulse, incites perspiration, and 

 produces a pleasant momentary irritatittn of the nervous s^'stem." 



Alter speaking of music as a moral agent, he thus treats of 



MUSIC AS A COMPLEX AGENT. 



It acts at once on the instinct, the forces, the organism. It has a psycho- 

 logical action. Tlie negroes charm serpents by whistling to them. It is 

 said that fawns are captivated by a melodious voice; the bear'is aroused 

 with tiie fife; canaries an sparrows enjoy the flageolet; in tlie Antilles, 

 lizards are enticed from their retreats by the whistle. Spiders have an af- 

 fection for fiddlers; in Switzerland the herdsmen attach to the neck of the 

 handsomest cows a large bell of which they are so proud that while they 

 are allowed to wear it they walk at the head of the herd; in Andalusia tlie 

 mules lose their spirit and power of endurance if deprived of the numer(jus 

 bells with which it is customary to deck these intelligent animals; in the 

 mountains of Scotland and Switzerland the herds pasture best to the sound 

 of the bagpipe; and in tlie Oberlaud, cattle strayed from the herd are re- 

 called by the trumpet. 



"Music being a phijsical agent, that is to say, acting on the individual 

 without the aid of his intelligence; a moral agent, that is to say, reviving 

 his memory, exciting his imagination, developing his sentiment ; and a 

 complex agent, that is to say, having a physiological action on the instincts, 

 the organism, the forces of the man — I deduce from tliis that it is one of 

 the most powerful means for ennobling the mind, elevating the morals, and 

 above all, refining the manners." 



Silvering Mirrors. 



At the Giessen congress Bothe's process for silvering glass was given. The 

 inventor uses oxytartrate of silver, in a solution of ammoniacal nitrate of sil- 

 ver, and produces beautiful results. 



Sound from Muscles. 



At the same congress Helmholtz presented a paper on the production of 

 sound from the contraction of muscle by which he is enabled to determine the 

 number of vibrations in the muscle. 



Pacific Telegraph. 



The regular discussion was opened by Dr. I. B. Rich, who exhibited maps 

 and diagrams of the Pacific railroad, and explained very clearly and minutely 

 its course. Ilis remarks, promised by him for this report, have not been 

 furnished. This debate naturally led to 



Electro-magnetism. 



The Chairman said it was important to remember the manner in whicti the 

 poles of an electro-magnet were changed by direction of the electric current. 



