i66 



The specific gravity- of the first fraction at 23° C. = 0-8404; of the second 

 = 0-8413; of the third =0-8515. The rotation of the first fraction ay, = + 

 35-7°; of the second + 37-2°; of the third + ^S-j"- The refractive index 

 of the first fraction at 23° = 1-4741; of the second = 1-4752; of the third - 

 1-4757. It is remarkable how closel}' the three fractions agree in the above 

 results. 



It is apparent that pinene could only have been present in small amount, 

 because the specific gravity and refractive indices differ but little from those of 

 pure limonene. 



The abo\-e results show the oil to differ entirely from that of C. glauca, 

 a species to which C . arenosa has, by some, been thought to belong. 



Neither sylvestrene nor phellandrene could be detected. 



The tetrabromide was prepared with the second fraction in the usual way, 

 and this, when cr3'stallised from acetic ether, melted at Ii7°-ii8° .C. When dis- 

 solved in cold acetic ether it was dextro-rotatory. It was fractionally precipitated 

 from acetic ether, when the first portion which separated on cooling melted at 

 122° C. ; the ne.xt at 119°, and the third at 117°. Better results were even 

 obtained by fractional precipitation from ether, the first portion melting at 

 I2i°-i22° C, and the latter portion at ii5°-ii6° C. 



The tetrabromide was readily prepared \\'ith the crude oil, and this (after 

 removing a very small amount insoluble in acetic ether) was identical with that 

 obtained with the second fraction ; it gave similar fractions by crystallisation, 

 which melted practically at the same temperatures, and were dextro-rotatory 

 also. 



It thus appears that the oil of this species consists largely of dextro-rotatory 

 and laevo-rotatory limonenes, the former being in excess, and that these when 

 occurring together in the plant behave similarlv to a mixed solution of the two 

 limonenes. 



No. 2. — Material was collected at Corrumbian Creek, and 414 lb. of terminal 

 branchlets with fruits gave 19^- oz. of oil, equal to 0-294 per cent. The crude 

 oil was insoluble in ten volumes of 90 per cent, alcohol. It was practically 

 identical with the previous sample, and contained the same constituents in about 

 the same amount. The specific graxity of the crude oil at 26° C. =0-8452; 

 rotation a^^ = -\- 18-9°; refractive index at 26° C. = 1-4764. The saponification 

 number was 10-2, equal to 3-57 per cent. 



The tetrabromide was prepared from the crude oil similarily with the 

 previous sample, and when purified from acetic ethtr it melted at ii8°-ii9° C. 



