98 Notice of some Recent [Feb. 



to the supply of materials, to throw together in a connected 

 form an account of some important improvements which 

 have recently been made in several branches of physical 

 science. The labour necessary in preparing such articles 

 as those individuals must be aware who have engaged in 

 similar avocations, is so considerable, that I trust to the 

 reader's indulgence in respect to any errors or omissions 

 into which I may have inadvertently fallen. 



I. ACOUSTICS. 



It has been recently observed by M. Breschet, that in many 

 of the chondropterygious fishes, as the skate, torpedo, &c, 

 there are open ducts, leading out externally, by which a 

 communication is established between the centre and the 

 membranous cavities of the labyrinth, while in many of the 

 osseous fishes, especially the cyprini or minnow tribe, and 

 the clupeae or herring tribe, &c, an opening exists between 

 the swimming bladder and the labyrinth. He has likewise 

 detected in the sacs of the labyrinth in man and vertebrated 

 animals, concretions which he terms otolites and otoconies. 

 (Ann. de Chim. 9 lvi.J. M. Cagniard Letour has obtained 

 some curious results from his experiments on the sonorous 

 vibration of liquids, and has attempted to explain the use 

 of the concretions observed by Breschet. In employing a 

 glass tube one metre in length, closed at the bottom, and 

 filled with water, he found that when rubbed with a moist 

 cloth, a sound was produced resulting principally from the 

 longitudinal vibration of the column of water, yielding 790 

 vibrations in a second. A syphon, open at both ends and 

 filled with water, under the same circumstances, afforded 

 an acute sound. Hence, we can account for fishes hearing 

 in cases where their auditory organs contained no gaseous 

 matter. He tried the effect of vibrations upon other liquids. 

 Several substances more dense than water afforded more 

 acute, others, more grave sounds than that liquid. 



Among the first are carbonate of potash at 71°, and muriate 

 of lime at 87°. Among the second, sulphuric acid at 150° ; 

 sulphuret of carbon and mercury. The same observation 

 holds with liquids possessing an inferior density to water. 

 He concludes, 1. That the liquids in human ears are con- 

 tained partly in species of tubes. 2. That these tubes or 



