— 90 — 
According to the conditions selected, there are, therefore, obtained 
the Hg-salts either of cineol, or of two isomeric trans-terpins ; by 
reduction with sodium amalgam or electrolytic hydrogen, trans-terpin 
of the melting point 156° can be obtained from the latter. 
The reaction took place in the same manner when applied to the 
dimethyl heptenol obtainable from methyl heptenone with C H3 • Mg • I. 
Minguin and de Bollemont^) have recently continued their work 
(discussed in our previous Report 2) on the rotation of the esters of 
Isevo-borneol, and have extended it to the esters of laevo - isoborneol. 
It was hereby found that the molecular rotatory power only becomes 
constant from the ester of valerianic acid, a fact which is attributed 
to the action of the lower acids splitting off water, with formation of 
inactive camphene, and the esterification of the latter into inactive 
isobornyl ester. The authors are of opinion that their supposition is 
confirmed by the fact, that the rotation of the isoborneol obtained 
from the esters by saponification is only constant in the preparation 
made from the valerianate, and that the lower homologues always yield 
isoborneol of constantly decreasing rotatory power. A sirailar regularity 
of the rotatory power could not be detected in homologue alkyl esters 
of camphocarbonic acid, presumably owing to the occurrence of 
compounds of the isomeric keto- and enol-forms, or of stereomerides. 
Substituted glycocollic esters of borneol and menthol have been 
produced by Einhorn andjahn^) by allowing bases, such as diethyl- 
amine and amido camphor, to act on the chloro-acetic acid esters of 
these alcohols. The diethyl glycocollic ester of menthol may possibly 
be interesting from a therapeutical point of view, as it forms a readily 
soluble hydrochloride, and in the organism splits off menthol. 
J. Kondakow and J. Schindelmeiser^) report on some derivatives 
of menthol. Like other secondary hydroaromatic alcohols, menthol also 
yields no uniform body when it is converted into menthyl halogen 
compounds, but on the contrary forms mixtures of secondary and 
tertiary compounds, whose quantities vary according to the reagent 
employed (phosphorus halogen compounds or concentrated acids of 
hydrohalogen), and to the temperature at which the action thereof 
takes place. If alcoholic alkali is allowed to act on these mixtures, 
the tertiary menthyl halogen compounds split off hydrohalogen much more 
^) Compt. rend. 136 (1902), 238. * 
-) Report October 1902, 94. 
^) Archiv d. Pharm. 240 (1902), 644. 
Journ. f. prakt. Chemie II. 67 (1903), 193. 
