o8 SECRETIONS. 



which it is obtained, and by distillation it is sepauu- 

 ted into two distinct ingredients : Oil of turpentine, 

 which is volatile, and Resin, which is not. If a quan- 

 tity of pine wood is collected, covered with turf, and 

 then set on fire, the resinous juice which would have 

 been dissipated in the open air, may be collected in 

 a suitable receptacle beneath. In this way, tar and 

 pitch, two well known articles of commerce, and both 

 of a resinous nature, are usually procured. 



Some of the most common examples of resin, are 

 Copal from a species of Sumach, Mastick from the Pis- 

 tacea, a tree which grows in the island of Chios, and 

 ^andarach from the common Juniper. From the Amyris 

 Gileadensis, a shrub which grows in Palestine and Arabi- 

 ans obtained a resin longcelebrated for itsmedical vir- 

 tues. It is the Balm of Gilead, so frequently alluded to 

 in sacred history, and it is still highly prized by the 

 Turks, who prohibit its exportation. 



On the epidermis of many vegetables, we find a soft 

 blueish powder which may easily be removed. It is 

 denominated the Bloom, and occurs on Plumbs, Cab- 

 bage leaves, and several other plants, always resisting 

 the action of water, but like the other resins readily 

 -oluble in alcohol. 



No kind of wood is so durable as that in which the 

 resinous secretion abounds. It is rarely injured by 

 those insects which devour the hardest timber, and 

 the insolubility of resin most effectually secures it 

 from the destroying agency of water. As a proof 

 of this fact, it has been observed that the Cypress 

 Sates of Constantinople, erected by the Emperor Con- 

 stantine, were found undecayed a thousand years after 

 they were built. It is owing to this secretion that 

 Pine is more durable than the hardest Oak, though at 



