316 Royal Institution of Great Britain. 



A microscope constructed for Capt. Grover, and the first con- 

 taining the application of Dr. Wollaston's doublet, was exhibited in 

 the library. It performed exceedingly well : it was made from the 

 model left by Dr. Wollaston to Capt. Kater. 



March 5. — The subject this evening was, On the transmission of 

 musical sounds through linear conductors, and their ultimate reci- 

 procation. It was delivered by Mr, Faraday, but he informed the 

 members that the matter, experiments, and new facts which he 

 should have to bring forward, were altogether Mr. Wheatstone's. 

 The general nature of musical sound was first distinguished from 

 noise, and then its transmission through different bodies illustrated. 

 The views gradually developed by Bacon, Hooke, and others, down 

 to the present time, were detailed, by which ultimately we had 

 gained much accurate knowledge of the conduction of sound through 

 solid conductors. 



After this the nature of the sounding-boards of instruments was 

 entered upon, and it was shown how the vibrations of a string, rod 

 or otlier almost inaudible phonic could be rendered strong and 

 powerful when transmitted to planes extended in the direction per- 

 pendicular to the course of the vibrations, and also how far the in- 

 closed volumes of air between the tablets of an instrument still 

 further exalted the sound by resonance, and rendered it evident. 



The conduction of sound by linear bodies and its ultimnle reci- 

 procation was then taken up, and numerous experimental illustra- 

 tions were adduced. A tuning-fork vibrating on the roof of the 

 Lecture-room had its vibration communicated inaudibly through 

 forty feet or more of deal rod to the floor below, and then the 

 sound developed by reciprocation ; so that those close even to the 

 tuning-fork referred the origin of the sound to the lower end of 

 the apparatus. Conducting rods and wires were passed through the 

 floor of the Lecture-room into a repository below, and the sounds 

 of a piano transmitted from below to a harp above, whilst the sounds 

 of the harp in the Lecture-room were transmitted to the piano- 

 forte below. The music of stringed instruments, wind instruments, 

 and even of the orchestrina or symphonium was equally well trans- 

 mitted, being rendered evident and audible only at the place where 

 by pre-arrangement their reciprocation had been provided for. 

 Mr. Wheatstone intends shortly to arrange the new matter which 

 he has been able to add to this branch of acoustical science in a 

 separate form. Parts of it are already before the public in the An- 

 nals of Philosophy, and Quarterly Journal of Science. 



INIarch 12. — This evening Mr. Brande gave an account of the 

 composition of Urinary calculi, and particularly of Dr.Wollaston's 

 discoveries in that branch of chemistry. He did this, he said, because 

 he was fully convinced that, if timely attention were paid to the 

 attacks of sand and gravel in their early stages, many persons would 

 be saved from the dreadful attacks of stone, and the evil cured be- 

 fore it had become unmanageable. 



After stating what had been done before Dr. Wollaston's time, 

 and then what had been effected by him, Marcet, Prout, and others, 



he 



