Notes on scientific research. 131 



concentration, is able to allow all lines to pass, but that if the concentration is suitably 

 chosen only a few, in many cases only a single, line passes. 



As already previously mentioned, von Auwers and Roth 1 ) have successfully made 

 use of the estimation of the thermic value in the determination of the constitution of 

 alicyclic compounds. Roth has now continued his researches in collaboration with 

 G. J. Ostling 2 ) and has found that Stohmann's law of the correspondence of caloric 

 value and dissociation-constants applies admirably in the case of the simple poly- 

 methylenic acids. 



Generally speaking, the serial sequence of the energy-content is as follows: 

 pentacyclic ring, hexacyclic ring, double-bond, tricyclic ring, quadricyclic ring. 

 Apparently a heptacyclic ring possesses a somewhat higher energy-content than 

 does a hexacyclic ring. So far as can be judged from the solitary compound which 

 has been examined, the spirocyclic arrangement of the carbon-atoms appears to be 

 fairly stable. 



Roth and Ostling have determined the thermochemical behaviour of the following 

 bodies which are of special interest to us: «-tanacetone dimethylcarboxylate, «-tanacetone 

 ketocarboxylic acid, cis-methyl norpinate, dimethyl pinate, methyl pinonate, c^/c/ofenchene, 

 thujane, thujylalcohol, thujone, and camphor. 



From the experimental results obtained by other authors, especially Vanstone j ), 

 Jouniaux 4 ), using the familiar thermodynamic formulas, has calculated the following 

 constants of camphor. 



Degree of heat at melting 8,23 cal. 



„ „ „ „ evaporation 93,17 „ 



Density of steam normal 



Ebullioscopic constant 50,2 



The values obtained by the different formulae are in satisfactory agreement. The 

 values given by Ramsay and Young were deliberately omitted. 



Pharmaco'physiological Notes. 



We may here refer to a paper by J. R. Rippetoe and L. E. Wise 5 ) on the conserving 

 action of essential oils. The authors investigated the development of mould-fungus in 

 solutions of glucose and of sugar-peptone in the presence of essential oils of the most 

 different descriptions. Among others, bitter almond oil, cajuput oil, citronella oil, clove 

 oil, eucalyptus oil and peppermint oil had a conserving action. Oils of angelica, lemon 

 sandal wood and turpentine, among others, were inactive, while with oils of Russian 

 anise, caraway, ginger, lemongrass, and a few others the effect was doubtful. 



H. Schwalb, in a thesis on comparative investigations in the pharmacology of the 

 terpene-series (Gottingen 1912) 6 ), describes a series of experiments made by him with 

 various terpene-bodies upon the hearts of frogs and upon paramaecia 7 ). Schwalb found 



J ) Lkbigs Annalen 373 (1910), 239; Report October 1910, 167. — ") Berl. Berichte 46 (1913), 309. — 

 3 ) Journ. chem. Soc. 97 (1910), 429. — 4 ) Bull. Soc. chim. IV. 11 (1912), 903. — B ) Jouni. Americ. pkarm. 

 Assoc. November 1912, I, 273; Pharmaceutical Journ.$9 (1912), 649. — 6 ) From a reprint kindly sent to us. — 

 ') Paramecium is a genus of infusoria. 



9* 



