The American Midland Naturalist 
PUBLISHED BI-MONTHLY BY THE UNIVERSITY 
OF NOTRE DAME, NOTRE DAME, INDIANA. 
VOL. Il. JULY, 1912. NO. 10+ 
MODIFICATIONS IN THE VENETIAN TURPENTINE 
METHOD. 
By C. M. HOPFINGER. 
Heretofore in working with the Venetian Turpentine method, 
fused calcium chloride only has been used as the drying agent 
in the concentration of the turpentine. There are however, other 
substances that have greater affinity for alcohol and alcohol 
vapor than calcium chloride. Definite compounds of alcohol 
and calcium chloride, as also of alcohol and zine chloride are 
formed in which the organic substance plays the role of alcohol 
of crystallization, the double compounds being analogous to those 
formed with water when the latter takes the part of water of 
crystallization. Moreover, just as these later substances liquify 
in their own water of crystallization and absorb even more than 
corresponds to the definite compounds, so alechol behaves towards 
the haloid salts of zine and calcium. Zinc nitrate would serve 
perhaps as well as the chloride unless oxidation products were 
formed. Another compound absorbing alcohol in the same manner 
as these mentioned is barium hydroxide.* 
Sulphuric acid behaves in a different way, absorbing alcohol 
* Some of these alcoholates, or in some cases ethylates, are the follow- 
ing, LiCl 4C,H;(OH)with wood alcohol LiCl 3C,H;(OH), Mg Cl, 6C,H;(OH), 
Mg (NO,), 6C,H,(OH),Na,$ C,H;(OH), CaCl, 4C,H,(OH), also CaCl, 3C,H;(OH) 
when dried over H,SO, SnCl, 2C,H,(OH) when heated gives off ether 
(C,H,),0, ethyl chloride, C,H;Cl; a compound C,H;O SnCl,+C,H,(OH) is 
formed also. TiCl,, PtCl,, SeO, AsCl,, SbCl, CuSO,, take up one molecule of 
C,H,(OH) to forma compound. KOH forms the compound KOH 2C,H,(OH). 
BaO and CaO form compounds which change to the ethylates, 
(C,H,O),Ba, ete. Wood alcohol acts somewhat similarly. I have not 
been able to discover whether a definite crystallizable compound of zinc 
chloride and alcohol has been isolated. 
t July 1° 1912.—Pages 249 to 264. 
