1814.] Scientific Intelligence. 317 



and provided with a complete and instructive catalogue, &c. &c. for 

 CO rix dollars, or about 10/. \0s. British. 



" Amateurs are requested to address themselves to Mr. Martini, 

 bookseller in Leipzig." 



The Editor of the Annals of Philosophy regrets that he is unable 

 at present to give any precise information respecting the inquiry of 

 his Correspondent. Immediately after the 1st of April he made 

 some attempts to procure a collection of minerals from Saxony; 

 but no satisfactory answers were returned to his letters. Indeed it 

 is not above six weeks since the Leipsic scientific journals came 

 into his possession, though they were ordered as early at least as the 

 month of March ; and even at present none have come to hand 

 later than for the month of May. All this is to be ascribed to the 

 dreadful state of confusion in which Saxony was left by the French 

 army. Some considerable time must elapse before matters get into 

 their usual train, and of course before there is any great probability 

 of being able to procure mineral collections from that country. 



VIII. Bricks that Sivim on Water. 



The ancients possessed the art of making bricks that swam on 

 water. Pliny names Pitane, an Asiatic town ; and Calenrum and 

 Mazilua, in Spain ; as places where the materials of these bricks 

 are found. Fabbroni some years ago discovered a substance from 

 which similar bricks might be made. It occurs at Castel del Piano 

 near Santa Fiora, between Tuscany and the States of the Church. 

 The substance in question constitutes a brown earthy bed mixed 

 with the remains of plants. Haiiy gives it the name of talc pulve- 

 rulent silicifere, and Brochant considers it as a variety of meer 

 tchaum. In Germany it is known by the name of bergmehl (moun- 

 tain meal), in Italy by that of latte di luna {moon milk). Klaproth 

 lately analysed it, and found it composed of 



Silica 79 



Alumina 5 



Oxide uf iron 3 



Water 12 



Loss 1 



100 



So that it nearly agrees with a mineral previously analysed by him, 

 to which he gave the name of kiese/^u/ir. 



Article XVIII. 



\>-u> Patents. 



Willi am Doncastjbb, Cavendish- square, London; for a scries 

 nprorementi in the construction, uses, and mode of navigating 



