ELISHA MITCHELL SCIENTIFIC SOCIETY. 23 



bark trees, growing in a sandy, dry soil ; if we have cut our 

 *^ boxes" properly, and attended them carefully, and had good 

 weather, we should get 280 barrels of 300 pounds each of 

 *' virgin (lip. 



What shall we do with it? How can we obtain spirits of 

 Turpentine and Rosin from it? By distilling it in a coj)per still. 

 Formerly iron stills were used, but they imparted a reddish tinge 

 to the spirits, so uow copper stills are used, holding froai 6 — 50 

 l^arrels of Turpentine, the ordinary size holding 15 barrels. 



Turpentine may be regarded as a mixture of spirits of Tur- 

 pentine, water and Rosin. The water, of course, boils at 100° 

 C, the Rosin melts at 100°, and above 150° C. is gradually 

 decomposed. The "spirits" l)oils at 158° C. Up to 100° C, 

 then, very little will come over except water. Mixed with the 

 water is a certain amount of pyroligneous acid, methyl alcohol, 

 ether, and, j)erhap^, formic acid, which mixture is termed ^'low 

 wine," and is frequently used by the laborers for kidney troubles. 

 As the heat rises above 100° C. the "spirits" begins to come 

 over, being yielded most abundantly, of course, at its boiling 

 point, 158° C. The "spirits" accumulates on top of the low 

 wine in the tub, and runs into a separate tub through a cock near 

 the top of the first one. Of course in such a viscid mass as " vir- 

 gin dip" it is only by long continued boiling, even at teuaperatures 

 above 100° C, that the water is expelled, so that a good deal of 

 water comes over with the "spirit^," and the boiling is kept up 

 until tht! proportion of spirits and water in an ordinary turabler- 

 full is 1 of spirits to 8 or 9 of water, i. e., from IJ — 2J hours^ 

 But where does all this water come from? It cannot all exist 

 in the Turpentine, and, so far as known, it is not a decomposi- 

 tion product. It is added to (he Turpentine in the still either 

 at the beginning of the distillation or after it has been in prog- 

 ress for an hour. Its office appears to be to assist in the expul- 

 sion of the "spirits," by causing a more violent bubbling and 

 boiling, with consequent vesiculation of the mass in the still. 

 Operating with " virgin dip," L e., the yield of the first year, the 

 distillation is stopped before all the "spirits" is driven off, so 



