&c. 



The nitric acid by which the stibic acid was separated from 

 the Valine mass, contains nitrate of potash. This saline mass 

 was, therefore, in fact, a stibiate of potash. 

 (To be continued.) 



II. 



Inquiries relative to the Structure of Wood, the specific Gravity 

 of its solid Parts, and the Quantity of Liquids and elastic 

 Fluids contained in it under various Circumstances ; the 

 Quantity of Charcoal to be obtainedfrom it - } and the Quan- 

 tity of heat produced by its Combustion. By Count Rum- 

 Ford F. R. S. Foreign Associate of the Imperial Institute 

 of France, &c* 



SINCE the days of Grew and Malpighi, there have been 

 but few regular inquiries into the structure of wood. The 

 science of botany has, indeed, taken an excursive range j and 

 the indefatigable zeal of modern naturalists, who have travelled 

 over all the known world, has made us acquainted with an 

 astonishing number of plants, unknown before in Europe, and 

 therefore called neiu , by which our gardens and apartments are 

 embellished with a profusion of gay flowers j but still the know- 

 ledge of the vegetable economy >s scarcely at all advanced. 

 The circulation of the sap in plants is still a subject of dispute, 

 and the causes of its ascension are very imperfectly known. 

 The specific gravity of the solid parts which form the wood of 

 plants, is unascertained, and, by consequence, the proportions 

 of solids, of liquids, and of elastic fluids ; the component parts 

 of a plant, with the variations to. which they are subject in 

 different seasons, are matters of which we are still ignorant. 



Jt is, indeed, known, that the wood of a tree remains and 

 preserves its primitive form after it has been converted into 

 charcoal j but no one has explained this extraordinary pheno- 

 menon, very little attention having been paid to it. 



An earthen vessel becomes hard and brittle in the potter's 

 furnace ; the vessel shrinks during the operation of baking, 



* Read at the sittings of the first class of the Institute, September 28, 

 andOetober 5, lbie. 



but 



