328 



ON PRETEXTING THE DECAY OF WOOD. 



Tlighly impor- 

 tant to preserve 

 wood from de- 

 cay. 



Two causes that 

 destroy it. 



Two kinds of 

 rot: 



wet, 



and dry, 



Dead matter 

 subject to de- 

 composition, 



only under cer- 

 tain circum- 

 stance?,. 

 Fi-h and other 

 anitnal matter 



II. 



An Inquiry into the Causes of the Decay of Wood, and the 

 Means of preventing it. By C. H. Parry, M, D.* 



JL HE power of wood in different forms to supply luxury, 

 to promote science, and to guard and prolong human life, 

 has made the means of preserving it from decay highly in- 

 teresting to mankind. With this view various premiums 

 have been offered by this and other ceconomical societies. 

 The object of the following discussion is to suggest the best 

 means of prevention, chiefly by inquiring into the nature 

 and sources of the evil against which it is intended to 

 guard. 



Wood, when killed by being separated from its root, is 

 subject to gradual destruction from two causes, — rotting, 

 and the depredations of insects. 



Of the rot there are two supposed kinds, as they affect 

 wood, first, in the open air, or secondly, under cover. 



The first is that which in the terms of our premium, 

 Class VII, No. 3, is said to occur to u barn and other 

 outside doors, weather-boarding, gates, stiles, and imple, 

 ments of husbandry :" To which, if there were any need 

 of this minute specification, might have been added posts, 

 rails, paling, water-shoots, and various other objects. 



The second is well known under the name of the dry. 

 rot, the cause and prevention of which are the subjects of a 

 premium by the Society of Arts in London. 



Animal and vegetable substances possess certain common 

 properties and movements, which constitute what is called 

 life. When that state ceases, and these properties and mo- 

 tions no longer exist, the bodies become subject to the che, 

 mical and mechanical laws of all other matter. 



When perfectly dry, and in certain degrees of tempera- 

 ture, both seem to be scarcely capable of spontaneous de- 

 cay. On this principle vast quantities of salmon are an- 

 nually conveyed in a frozen state to London from the north 



* From Papers of the Bath and West of England Society, 

 vol. XI, p. 226. 



Of 



