2o 



1 



)r 



hrs 



are 





1 



ft 



^^'^ that 



^h ; the 



-4; the 



- j^^ and 



Ider 



pro 



^ce ; and 

 er tree 

 the mod 

 «mand of 



wood ! 



!S 



to be at- 



.htning; 

 allv fup- 



fe which 

 crack- 

 ent this, 



to a few 



futn- 



deby 



}e 



eir 



m 



to 



injury 



x 



there- 



ao 



in 



111 



a 



lathes ^' 







thefs 



/ 



* 



Sect. XVIII. 2. 5. LEAVES AND WOOD. 



5^9 



\ 



r 



L 



Others are ufed in the art of dying, as the Campechy wood, hasma^ 

 toxylum, and faunders, fantalum, and pterocarpus ; and feveral 



« 



others. Other woods differ in their medicinal properties, as guaicum, 

 quafiia, Campechy wood, and faflafras. Others differ in their che- 





mical properties 



affording 



efTential oils, as oleum rhodii, and 



turpentines or balfams, and tar ; and in their reftringency, as the 



oak. 



5. The oak probably contains much gallic acid, fuch as has beea 

 traded from the galls occafioned on their leaves by the pun6lures 



I 



of inrc(£ls 



hence oak boards are faid 



corrode the (heets of lead 



which are laid on them, and are hence believed to be improper for 

 the guttu re-boards on the roofs of houfes. But the fap-wood, or ex- 

 ternal part of all timber, I fufpedl, mufl be improper for this pur- 

 pofe on another account ; as, when confined from much air by the 

 fheet of lead over it, it muft lie for many months in th 

 that (late of moifture, which will favour 



th 



J year in 



fermentation of the 



faccharine matter, which all fap-wood contains; and will thence be 

 fubjed to the dry rot, as it is called by architedls. This may be lono- 

 prevented by leaving proper holes in the walls on all fides the build- 

 ing immediately under the roof, as has been generally done by thofe 

 itinerant bodies of architeds, who (hewed fuch prodigies of genius In 

 the conftrudion of cathedrals in this ifland, and all over Europe ;. and 



hofe fecret identifying word 



d 



federate figns, which w 



t 



eceflary to them in foreign countries,vvhofe language they had 

 me to acquire, feems to have given origin to the modern myfte 

 of Free-mafonry. 



The rot of wood might probably be entirely prevented by foak 

 dry timber firfl in lime- 



( 



water 



has abforbed as much of 



may be ; and then after it is dry by foaking it in a weak folution of 



will unite with the. lime already de- 



id 



hich 



pofited in the pores of the timber, and convert it into gypfum ; which^ 

 1 fuppofe will not only prefervejt from decay for many centuries, if 



III 



I 



— ' 



