The data given in the previous article dealing with the comparative constancy of the oil products, only treat with those distilled from general material, and not from individual trees or selected growths. In order, therefore, to determine the variation in amount of constituents in oils from such material that might be expected, the following work was undertaken.

With the exception of two samples of E. Smithii (f and g), which were distilled by Mr. D. E. Chalker, of Hill Top, New South Wales, from general material, all were prepared at the Technological Museum, the leaves having been specially collected for the investigation, and with the exception of (e) all were from naturally growing trees.

The results dealing with the oils of E. Smithii were published in the Proc. Roy. Soc, N.S.W., August, 1915.

The material worked on is represented by the following stages of growth: -

(a) Leaves from lopped trees, seven months' growth; collected May, 1913.

(b) Reaves from lopped trees, fifteen months' growth; collected May, 1913

(c) Leaves from seedlings, twelve months' growth; collected June, 1914.

(d) Leaves from seedlings two and a half years old; collected July, 1914.

(e) Leaves from tree cultivated at Marrickville, near Sydney; collected

June, 1915. (Tree, 3 1/2 years old). (f) Leaves from general material, partly young; collected January, 1915. (g) Leaves from general material collected three weeks later than (f). (h) Leaves from old trees; collected March, 1913. The constants, etc, given by the crude oils from the above material were as follows: -

Specific gravity at 15° C.

Optical rotation

aD.

Refractive index at 200 C.

Solubility in 70 per cent. alcohol.

Saponification number.

Cineol. per cent.

Required.

(a)

0.9098 ....

+ 7.6°

1.4636

1.6 vols.

4.8

67.4

(b)

0.9157 .......

+ 6.5°

1.4635

1.2 „

5.6

74.2

(c)

0.9116 ....

+ 9.2°

1.4654

2.1 „

1.3

61.5

(d)

0.9139 ...

+ 7.6°

1.4643

1.4 ,,

4.1

69.0

(e)

0.9198 ...

+ 47°

1.4690

1.2 „

2.7

75.0

(f)

0.9156 ....

+ 5.3°

1.4599

1.1 ..

3.3

80.7

(g)

0.9154 ...

+ 5.1°

1.4597

1.1 „

3.1

79.0

(h)

0.9210 ...

+ 4.2°

1.4613

1.1 ,,

1.3

85.2

The cineol was in all cases determined by the resorcinol method, in the redistilled portion of the freshly obtained oils boiling below 1900 C. and calculated for the original oil.

It will be noticed from the above table that the oil from the younger seedlings contained more dextro-rotatory pinene and less cineol than did that from the saplings two to three years old, and that the maximum cineol content was reached in the oil from leaves collected from older trees. This is true also for the leaves which are reproduced from lopped old trees and the oil from the seven months' "suckers" contained more cineol and less pinene than did that from twelve months' old seedlings, while that from the fifteen months' old "suckers" followed the same rule in respect to the two and a half years' old seedlings. It will be seen that the constants followed this change in constituents somewhat regularly. To a small extent these were governed by the length of time to which the leaves had been distilled, as naturally the heavier constituents were brought over with more difficulty. The factors which are influenced to the greatest extent appear to be the specific gravity and refractive index, and this was shown with V), where the idea was to obtain, by longer distillation, as much of the crystallised eudesmol as possible. With (f) and (g) derived from general material commercially distilled, the oils were quite in agreement with those we obtained when this species was first investigated many years ago, which results are recorded under E. Smithii in this work. Thus the relative constancy with the oil of individual species is again shown.