400 



TlIH LniONENE. 



The fraction 173-177° C. was treated with bromine, in a well cooled acetic 

 acid solution, for the preparation of the tetrabromide. Crystals did not readily 

 form, but e\'entually they were obtained in some quantity; when liltered at the 

 pump, and purified tioin acetic ether, the crystals melted at 104° C. This result 

 shows that the higher boiling strongly dextro-rotatory terpene is limonene, and 

 that dipentene is absent. The amount of limonene in the oil can hardly exceed 

 ID per cent. 



The Pinene. 



The fraction 156-159° C. was treated with amyl-nitrite in a well-cooled 

 acetic acid solution, when crystals of the nitrosochloride soon formed. These were 

 filtered off, dried on a porous plate, and purified by dissolving in chloroform and 

 precipitating with methyl alcohol. The melting point was 110-111° C. As all 

 the indications were in favour of pinene, this high-melting point of the nitroso- 

 chloride was evidently due to the presence of a small amoimt of the principal 

 terpene still remaining with the pinene. The lower boiling portion of the oil is 

 evidently l«vo-rotatory pinene, of which constituent the oil contains about 10-15 

 per cent. 



The Principal Terpene. 



The nitrosochloride prepared from a portion of the oil boiling at 161-165° ^• 

 melted at 119-120° C. (cor.). It thus appeared that a previously tmdetected 

 terpene was present in this oil and in some quantity. It could not be camphene, 

 because the nitrosochloride was formed with it so easily, even surpassing pinene 

 in this respect. 



The nitrosochloride prepared from the finally rectified oil boiling at 

 165-166° C. melted at 120-121° C.(cor.); so that it was only possible to increase 

 the melting point by i degree above that of the nitrosochloride prepared from 

 the fraction 161-165° C. 



Xitrosochloridcs ul the mcutliencs, which had a liigh melting jxtint, 

 have been prepared by Kremers and coadjutors, and also by Baeyer, but the 

 physical results, and the analysis of Dacrydene, show that it cannot belong to the 

 C,„H,« series of hydrocarbons. The odour, too, had no resemblance to menthene. 

 (See also under Callitris Macleayana, in this work.) 



An analysis was made witli results whirli showed Dacrydene to have the 

 C,„H,B formula. 



o-iio8 gram gave 0-1162 gram H./3, and o-35<Si gram CO2. H. = 11-65 

 per cent., and C. = 88-14 per cent. ' 



C,„H,u requires C. = 88-24 ''ind II. = 11-76 pe-r cent. 



