204 



H. G. SMITH. 



carried out under reduced pressure, so that they are strictly com- 

 parative. The temperatures given are those of the oil at the time 

 the specific gravities were taken, and all are given against water 

 at 16° C, except of course the determination of the pinenes at 4° 0. 

 The rotations were taken in a 200 mm. tube, the specific rotations 

 being calculated from ~ the temperatures of (d) being those stated 

 in the paper. 



On mixing equal volumes of the two pinenes, the rotation in the 

 200 mm. tube was - 6*2° showing that the dextrototatory pinene 

 had neutralised exactly the same amount of rotation of the 

 lsevorotatory form. 



By referring to the results it will be seen that the specific 

 gravities of the several fractions of the two oils, their rates of 

 distillation and the percentage amounts distilling below 172° C. 

 are fairly concordant, with the exception that the oil from E. 

 Icevopinea boils at a slightly higher temperature than that from 

 E. dextropinea. The real difference between these Eucalyptus 

 pinenes is their extreme opposite rotation, and while the specific 

 rotation of the dextrorotatory Eucalyptus pinene is twice as great 

 as that observed in the pinene (australene) from dextrorotatory 

 oil of turpentine, the specific rotation of the lsevorotatory 

 Eucalyptus pinene is greater than that of the pinene (terebinthene) 

 from lsevorotatory oil of turpentine. 



The Eucalyptus pinenes are identical in appearance, being 

 colourless, mobile liquids, having an odour with a slight resem- 

 blance to ordinary oil of turpentine; the dextropinene has more 

 markedly the odour of ordinary oil of turpentine than has the 

 lsevorotatory form. 



The nitrosochlorides. 



One volume of the pinene was added to one volume of amyl 

 nitrite and the mixture dissolved in two volumes of glacial acetic 

 acid ; this was cooled in a freezing mixture of ice and salt, and 

 concentrated hydrochloric acid and glacial acetic acid, in equal 

 parts, slowly added while the blue colour remained ; it was then 



