414 Notices of Memoirs — Francesco Castracane 



Mr. Mallet's positive assertion that the " convex surface of a fracture 

 {i.e. joint) always points in the same direction as that in which 

 the cooling proceeded." That this mis-statement of the fact is 

 not a casual error is shown by further passages, in which (page 

 183) it is asserted that if the cooling commences from the top 

 surface of the bed, the " convex surfaces of the cross joints all 

 point downwards ; " whereas if the mass cooled from the bottom, 

 the " convex surfaces of the joints of the lower prisms point 

 upwards." Mr. Mallet's theory, therefore, rests, unfortunately 

 for him, upon a false assumption, which he might easily have 

 ascertained for himself without stirring from London. 



Mr. Mallet, however, may perhaps reply that his theory is correct, 

 whether the assumption on which it rests be true or not, since I 

 observe from an article in the latest number of the Proceedings of 

 the Eoyal Society (162, vol. xxiii. page 444), that he still adheres 

 to his preposterous notion of a Geyser underlying the volcanic vent 

 of Stromboli, — even though it has been demonstrated to him that the 

 steam and water tube required on this supposition must be at least 

 2000 feet in depth ! He takes no notice, moreover, of the many 

 arguments employed by me in the paper to which he refers, 1 against 

 his theory, besides the height of the crater-floor 2 above the sea-level 

 — any one of which is alone sufficiently conclusive as to its unten- 

 ability. 



1TOTIOES OIF IMIIEDUCOIIR-S. 



DlATOMACE^I IN THE CARBONIFEROUS PERIOD. 3 



By Signor, Count, Abbot, Francesco Castracane. 



(Translated by Miss L. H. Littledale, Dublin.) 



80 great is the importance of Coal, which constitutes the chief 

 wealth of some favoured countries, and is the principal lever of 

 England's power, that no one will wonder that its nature, its 

 mineralogical properties, and the history of its formation, have 

 claimed the attention of scientific men. This valuable substance, in 

 which Nature has preserved to the feverish activity of our century 

 the principal aliment of the metallurgic industry, of arts and com- 

 merce, has been the subject of the learned researches of many highly 

 distinguished naturalists and geologists. They have examined 

 the impressions of the many vegetable and animal remains which 



1 Geol. Mag. Dec. 1874. 



2 Bye-the-bye, why will Mr. Mallet persist in calling the bottom of the crater its 

 "fundus " ? Fondo is, no doubt, the word in use for it among Italian writers. But 

 our own language possesses more than one synonym for the thing intended, any one 

 of which would better express the idea to English ears. So, too, in the article on 

 columnar basalt, the French word " couche " is always used by Mr. Mallet in lieu of 

 our native synonyms of "layer," "zone," or "film," all equally expressive of his 

 idea. Other writers, likewise, on volcanic subjects, still continue following the bad 

 example set by Dr. Daubeny, in speaking of a " coulee " of lava, when they mean a 

 " stream " or " current," words equally expressive of a once fluid or flowing mass. 



3 "LeDiatomacenellaEta delCarbone." Extracted from the Atti dell' Accademia 

 Pontificia de' JSfuovi Lincei," Borne, 27th year, 3rd session, February 22, 1874. 



