356 Wisconsin Academy of Sciences , Arts and Letters. 
befreiten,”) substance they assign to it the formula C 10 H 16 + H 4 O 2 
__ qi° H oo q 2? consisting therefore “ aus einem Atom Terpenthinol und 
einem Atom Wasser.” 
Blanchet (Annalen, Bd. 7, p. 167) obtained “ Terpenthinhydrat ” 
“ durch vermischen des Oels (Wacholderbeerenoel) mit Wasser und hin- 
stellen desselben in gewohnlicher Temperatur, wo denn nach einigen 
Wochen das Hydrat an den oberen Wdnden des Gefasses krystallisirt 
According to such a method pinol hydrate is obtained, not terpin 
hydrate. 
14 That Stenhouse, according to Wiggers’ method, should not have ob¬ 
tained terpin hydrate, but a substance “C 5 H 4 -j- HO” (i. e. C 10 H 20 0 3 ) 
seems strange indeed. Analyses, physical properties and the odor of the 
dehydration product do not harmonize with those of terpin-hydrate, but 
with those of pinol-hydrate. 
15 Attempting to prepare terpin hydrate in one experiment (Annalen 
Bd. 57, p. 247) Wiggers obtained according to his well known method 
campher ” within half an hour, which, however, disappeared after sev¬ 
eral hours. After that no further crystals would result. It would ap¬ 
pear from the text that Wiggers had shaken the bottle whereupon the 
crystals dissolved. Under these conditions pinol hydrate might form 
in so short a time, but not terpin-hydrate. 
List (Annalen, Bd. 67, p. 362) essentially verifies Wiggers’ statements, 
and calls special attention to the fact that one molecule of water in ter¬ 
pin hydrate is present as water of crystallization. 
Deville (Annalen, Bd. 71, p. 346) adds very little new. It is of interest, 
however, to note that he recognized the identity of the dipentene dihy¬ 
drochloride obtained from terpin hydrate with that obt. from lemon oil. 
16 Sobrero first recognized the fact that by the action of oxygen in the 
presence of sunlight a hydrate is formed which differs from the “ Terpen- 
tinolhydrat ” of Wiggers. He assigns to it the formula “C 20 H 16 0 2 -f- 
2 H O” [i. e., C 10 H 18 0 2 = C 10 H 16 O -f- H 2 O]. This substance recently 
designated as “ soberol ” by Armstrong (J. C. S., vol. 49, p. 315), is noth¬ 
ing more or less than Wallach’s pinol hydrate (Annalen, Bd., 259, p. 313.) 
17 A compilation of the various crystallagraphic measurements can be 
found in Rammelsberg “ Handbuch d. kryst. phys. Chemie.” (1882) p. 449 # 
18 According to Vulpius, J. C. S., 56,1202 (from Chem. Centr., 1889, p. 789, 
from Pharm. Centralhalle, 30, 289.) The statement that terpinhydrate is 
soluble in 200 p. of cold and 22 p. of boiling water (Realencyclopgedie der 
gesammten Pharmacie IX, p. 645) can be traced back to Blanchet and 
Sell (Annalen, Bd. 6, p. 266). It has been indicated that these chemists 
very likely had no terpin hydrate in hand but pinol hydrate. 
19 An alcoholic solution does not decolorize bromine; Wallach: (Anna¬ 
len, Bd. 230, p. 248.) 
20 Ibidem. 
