M. Savart on the Elasticity of Crystals. 141 



mer, indeed, is unworthy of its name, being a mere emissary of 

 sulphuretted hydrogen, without even a deposition of sulphur 

 beds. * The latter presents many phenomena similar to the 

 Solfatara of Pozzuoli, including the emission of sulphuretted 

 hydrogen and steam at a high temperature, with the deposition 

 of sulphur and several salts. In the opinion of some, the phe- 

 nomena are even more interesting than the more frequented 

 display in the Bay of Naples, but they have excited compara- 

 tively little attention, especially among English writers. •[• At 

 all events they deserve at present particular observation, since 

 it is the opinion of Breislak, and perhaps not devoid of plausi- 

 bility, that while the Solfatara of Pozzuoli is becoming gra- 

 dually extinct, the phenomena of the Tuscan Lagunes tend to- 

 wards a state of perfect inflammation. 



Art. XXI. — Researches on the Elasticity of regularly cry- 

 staliized Bodies. By M. Felix Savart, Member of the 

 Academy of Science. 



This very able and interesting memoir was read before the 

 Academy of Sciences at Paris on the 29th January 1 829, and 

 has been printed in the Ann. de Chimie for January and Fe- 

 bruary. The object of the author is to determine the distri- 

 bution of elasticity in solid bodies, and consequently their 

 structure, by cutting plates out of them in various directions, 

 and ascertaining the sound which they emit while vibrating, 

 and the modes in which they divide themselves, as rendered 

 visible by the figures formed by sand or lycopodium strewed 

 on their surface. A condensed abstract of this curious paper 

 is all that our limits will permit us to give. 



M. Savart'*s first experiments were made upon wood, the struc- 

 ture of which he has analyzed by means of sonorous vibrations. 

 The phenomena are here related to three rectangular axes of 



• While this sheet was passing through the press, I accidentally read 

 the Abbe Nollet's account of this place in the Memoires de VAcademie, 

 1750, p. 65, 4to edit., where I find a true sulphureous deposition noticed. 

 In fact, there are two emissaries of sulphuretted hydrogen in this locality, 

 the Solfatara, properly so called, and the I.ago dei Tartari. 



t A full account will, I believe, be found in " Sanii, Viaggii d'Isioria 

 Naturale" 3 vols. 8vo, and in the work of a German, named Prystanowski. 



