— 161 — 



inasmuch as such slight differences in the distilling-temperature as Vio° 

 * were perceptible in the shape and position of the absorption-curve. The 

 curves of the preparations under examination have been plotted by Hantzsch 

 in several tables, in which on the vertical lines he gives the logarithms 

 of the layers in mm., corresponding to 1 /i 00 o normal solutions, and on the 

 horizontal line the oscillation-figures in the ultra-violet rays. The absorption 

 increases in proportion to the nearness of the double-linkings. It is weakest 

 in pinene with the bridge-linking and in limonene with the greatest distance 

 of two double-linkings; it increases in strength as the double-linkings 

 draw nearer together (as in sylvestrene), and it reaches its maximum in 

 the conjugated linkings, conjugation outside the ring (/?-phellandrene) being 

 more active than that within the ring («-phellandrene). 



A paper by J. F. Eijkman 1 ) on the refractometric behaviour of a series 

 of organic bodies contains particulars of the refraction and density of 

 certain terpene-bodies: — 



Formula 



t 



n« 



Pulegane . 



Pinic acid 



Z-Pinonic acid . • . . . . 



«-Pinonic acid 



«-Thujaketonic acid . . 



Pulegenic acid 



Puleganic acid 



Ethyl puleganate. . . . 

 Puleganic nitrile . . . . 

 Pulegano lactone . . . 

 J 4(8) -Menthenol-l .... 

 J 8(9) -Menthenol-l .... 



Fenchone 



«-Fencholenic amide . 

 y2-Fencholenic acid . . 

 AFencholic acid amide 

 ^-Fencholic acid .... 



C9H18 



C9H14O4 



C10H16O3 



C10H16O3 



C10H16O3 



C10 Hi6 O2 



C10H18O2 



C12 1122 >^2 



C 10 H 17 N 



C10H16O2 



Ci H l8 O 



CioHisO 



CioHieO 



C 10 H 17 ON 



C10H16O2 



C 10 H 19 ON 



Cio H18U2 



15,2 



109,4 



110,7 



109,1 



79,6 



17,5 



20,2 



11,8 



16,2 



21,0 



80,0 



79,8 



14,5 



117,9 



76,1 



108,2 



18,9 



0,7799 

 1,0925 

 1,0257 

 0,9975 

 1,0115 

 1,0035 

 0,9618 

 0,9178 

 0,8814 

 1,0146 

 0,8948 

 0,8703 

 0,9488 

 0,9331 

 0,9638 

 0,9072 

 0,9698 



1,42744 

 1,44581 

 1,44621 

 1,43812 

 1,44747 

 1,47989 

 1,45201 

 1,44047 

 1,44751 

 1,46048 

 1,46277 

 1,44612 

 1,46232 

 1,46216 

 1,45861 

 1,44683 

 1,45469 



t G. Ciamician and P. Silber 2 ), in their twelfth paper on the chemical 

 action of light*), describe the effect of light upon toluene, p-, m- y and 

 o-xylene, p-cymene, phenanthrene, and p- and o-nitrotoluene. The _p-cymene 



!) Chem. Weekblad 8 (1911), 651. Quoted from Chem. Zentralbl. 1911, II. 1029. 

 2 ) Comp. Report October 1907, 123; October 1909, 159; October 1911, 122. 

 *) Berl. Berichte 45 (1912), 38. 



11 



