184 Foreign and Miscellaneous Intelligence. 



and kept for any length of time without change, being always recon* 

 vertible into useful states by the mere addition of water*. 



16. MANUFACTURE OF CHARCOAL. 



A new process, recommended in the Journal des Fore/5, for this 

 purpose, is to fill all the interstices in the heap of wood to be charred 

 with powdered charcoal. The product obtained is equal, in every 

 respect, to cylinder charcoal ; and, independent of its quality, the 

 quantity obtained is very much greater than that obtained by the 

 ordinary method. The charcoal used to fill the interstices is that 

 left on the earth after a previous burning. The effect is produced 

 by preventing much of the access of air which occurs in the ordinary 

 method. The volume of charcoal is increased a tenth, and its weight 

 a fifthf. 



Mr. Doolittle, of Birmington, United States, has lately charred 

 wood in kilns constructed for the purpose. One was built of brick- 

 work, thirty feet diameter and nine feet high, to the opening of the 

 arch which inclosed the top. It had openings at the top and sides 

 for the purpose of admitting air, charging, extracting, &c., all which 

 openings were under regulation. The charcoal thus obtained was 

 exceedingly good in quality, free from stones, earth, &c., and very 

 abundant in quantity, the increase being, in the latter respect, some- 

 times half as much more as the old mode of burning would givej. 



17. POTASH OBTAINED COMMERCIALLY FROM FELSPAR. 



According to M. Fuchs, this important alkali may be extracted 

 from minerals containing it, by the following method : They are to 

 be calcined with lime, then left for some time in contact with water, 

 and the liquor filtered and evaporated. M. Fuchs says he has thus 

 obtained from nineteen to twenty parts of potash from felspar, and 

 from fifteen to sixteen from mica, per cent. 



18. SALE OF SELENIUM. 



Perfectly pure selenium (free from sulphur) is announced for sale, 

 at the price of four gold Frederics (ninety francs) per ounce of 

 Cologne (446 grains). Applications, post paid, with the money, is 

 to be made to the Ducal Office of the Mines of Harzgerode, in the 

 duchy of Anhalt. 



* Ann. de Chim. xliii. 337. f Bull. Univ., D. xiv. 262. 



J Silliman's Journal, xvii. 395. Ann. de 1'Industrie, v. 278. 



