508 TRANSACTIONS OF THE 



the coal is brought in contact with the posts to be preserved, and 

 they must then be exposed to the influence of rain, which dis- 

 solves the sulphate of iron, and causes it to enter the pores of 

 the wood, impregnating them with preservative metalic salts, by 

 the process of nature's elements, which under any other circum- 

 stances are the most destructive to wood, producing rot by coming 

 in contact with its tannin, and causing it to unite with oxygen, 

 for which it has a great affinity. 



Dr. Broucherie, of Paris, charges the sap tubes of posts, tele- 

 graph poles, railroad sleepers, etc., with preparations of zinc, 

 iron, and sundry other metals, thus : a cross-cut is made on the 

 prostrate timber to nearly nine-tenths of its diameter, a wedge is 

 then inserted, and a cord is wound round on the cut surface, 

 leaving a shallow chamber in the centre, which is then closed by 

 withdrawing the wedge, A tube is then inserted through an au- 

 ger hole into this chamber, and to this tube is attached an elastic 

 connecting tube from a reservoir placed some twenty or thirty 

 feet above the level in which the wood lies, and a stream of the 

 saturating fluid, with this pressure, passes into the chamber, 

 presses on the sap in the sap-tubes, expels it at each end of the 

 log, and itself supplies its place. An admirable fluid for this 

 purpose, is a solution composed of sulphate of copper and water, 

 which will render green pine wood capable of resisting decay. 

 Pyroligneous acids may likewise be used advantageously. 



R. L. P. 



Solon Robinson — I hold in my hand an item of valuable infor- 

 mation for farmers upon this subject. It states that James Trim- 

 ber, of Hillsboro, Ohio, put up some post and board fence in the 

 fall of 1844, the posts of which were oak that was cut the January 

 previous, and sawed 2 by 3 inches at the top, and 2 by 6 

 inches at the bottom; but in sawing the largest end of the posts 

 were made from the top end of the log, so that when set they 

 stood inverted from the way in which the tree grew. These posts 

 were packed around with limestone; " and," savs Mr. T., " they 

 are good and sound now. Posts of the same timber, set at the 

 same time, packed with dirt, and without being inverted, are three- 

 fourths rotted and worthless. I am now renewing my fences, 



