??ov.'2, 1903.] THE TKOPICAL AGRlCULTtmiST, 
Snch a system wonld, if closely followed, practically 
MPtrict thfi farmer's nltimate pnrehases to a ptnall 
qnantitv of acid phosphatpe, or of bone dnat, which, 
in coDjnnction with good tillage, shonld serve to 
maintain the grove in a highly productive condition 
for an indefinite term of years. 
EUCALYPTS. 
Your reviewer of two recent works on Encalvpts 
Beepifl to reqnire correction on certain poin^n. 
F.ucahiptus r/lobulun cannot be considered as the 
first in economic importance nmnngst the Encalvpts. 
In almost every Rbsde of ey^ra-'cnnicnl climate there 
ia to be found n Bn^alypt which will grow ti'f well, or 
better, than E. qlohvJw. and yield a far snpenor timber. 
It is generally held now that Encalypt 'planting: has 
gmfferpd by the indiscriminate praise showered i)n E. 
gh.hulus, bv the early Encalypt enthnsiaats. 
Yonr reviewer says, fnrther, thit Encalypt' planta- 
tions now exist in Italv, France. Algeria, Ca'iforrin, 
and other countries. He does not cpnear to be aware 
that there is nrnbablv more Encalfpt plantation in 
Sonth Africa than in any othor conntrv. and that at 
the present rate of progress there will, in a few 
years, be more Encalypt plantations in South Africa 
than in all the other countries combined. There is 
DO group of trees in the warm temperate regions 
of the world that can produce hardwoods of good 
quality bo rapidly and bo cheaplv as Eucalvpts. and 
their cultivation bids fair to become the central 
factor in the forestry of these regions. At this 
moment train-loads of Encalypt timber are pouring into 
South Africa, Encalypt sleepers displacing metal and 
creoBOted-pine sleepers. South Africa will soon be 
paying out something like a tjuarter of a miUion pound' 
iiearly for Encalypt timber imported for railwn.y slee- 
pers and mining timber (little or none of this, by 
the way, E. qlohulns). so that sny delay in the prose- 
cution of Euoalypt planting in South Africa would 
be a most expensive proceeding. It is noteworthy 
that, BO lone as the Encalypt is prope'-lv fitted to 
its olimate, it seems to grow better in South Africa 
than in Australia, the explanation being probably 
that all the Eucalypts in South Africa have been 
raised from seed, and are thus growing in South 
Africa free fr-^m their Australian pests, both fungoid 
and insect. With the view of preserving this happy 
immunitv from disease, the importation of Encalypt 
plants into Cape Colony is placed under stringent 
re»t>-ictions. 
The meritorious work of Messrs. R. T. Baker and 
H. Smith, if carried to a conclusion, should be 
the classic for many years on Encalyptua oil. Your 
reviewer is mistaken in saying that practically all 
the Encalypt species indigenous to Australia are in- 
cluded in their work. Practically, all the Eucnlvpts 
are indigenous to Australia, but thev are not included 
in Messrs. Baker and Smith's work, which embraces 
111 out of 120 described species of New South Wales 
and a few others from the neiehbou'^ing colonies of 
East Australia, but none of the well knrwn timber 
Eucalypts of Western Australia, Jarrah, Kari, Touart, 
red gum, York gum, &c. 
It ia a little disappointing that th? authors were 
unable to obtain leaves of such a prominen Eucalvpt 
BS Encalypfus rer/nans, the tree which shares with E. 
diversiclor the honour of being the tallest tree in the 
world It is common enough in the 'rovernment 
plantations neai" Cupe Town, as is also E. alpina^ 
which figfires al^o in the jist of unprocurables- It 
is particnlarlv unfortunate that they have not tested 
Eucal,/f*u..i cnJnphi/lhi. the tvpo of the parallel veined 
Euoalrp'i' ' •• a ^est An .trali-^n Siiecies. 
MeR • ■ - ■' Smith st^ite that forty tons of 
Euoftlv, ; ' ' '-d and 500 di = tillition^ roidp. 
Their work is a moael of painstaking investigation 
and to the chemist and those interested in the oil 
iodnatry will ao doabt prove extremely aaefal. 
But the authors have not confined themselves to 
the chemistry of Eucalyptus oil. They propose a 
number of new Encalypt species and a new classifi- 
cation of Eiioa'ypts. How f.ar the numerous new 
species will ptand the test of critic'vl invpstigjition 
in the field remains to be seen. Many of their new 
species have already been contested. 
THE RELATION BETAVKEN LEAVES AyD OIL. 
Messrs. Baker and Smith have discovered that 
there is a relation between the venation of Encalypt 
leaves and the chemical constitution of the oils of 
those leaves. Parallel veins and pinene go together. 
Many of the parallel veined leaves smell of turpen- 
tine like a pine leaf. Then come the peppermint 
EacalyptR, containing piperitotie, with a more com- 
plex venation ; and then a still more complex 
venation yielding oils rich in enc-lyptol or cineol, 
which^ is the valuable constituent in the best Eucalypt 
oils. Thi^ is a very interesting and important corre- 
lation, especially if further investigation shows that 
it holds good through fie whole Encalypt genus. 
As chemists one can pardon the authors their en- 
thuaiaera ovi-r it. But whether it? is suflficient to 
found a new classification of Eucalypts on may be 
doubted- We have numerous Eucalypt cln.ssificationa 
in the field. There is that which is generally accepted 
in default of a better, the anthereal system of 
Bentham, somewhat modified and simplified, but 
not improved in Mueller's subsequent works. There 
is a (perhaps more practical) bark system, and there 
are various obsolete systems founded on the shape of 
the cones and the flower buds. As Messrs- Baker 
and Smith most justly remark, a natural classification 
founded on a combination of all these, including the 
quantity and structure of the timber, has yet to be 
made. It is not likely that their oil-and-veiu classi- 
fication will be sufficient in itself. It seems unlikely 
that anyone, except a scientifically trained forester, 
who has spent a large portion of his life among the 
Eucalypts in their natural forests, will be able to 
construct a sound natural grouping of the species of 
this difficult genu°. The work will require a Mathiea 
a Brandis, or a Gamble, that is to say, a practical 
forester with special scientific qualifications. It is 
not to be done with botanical specimens as Bentham 
and Mueller attempted it, nor with practical know- 
ledge alone as Wools attempted it, nor in a chemical 
laboratory where 'MesBrs. Baker and Smith have done 
most of their work ! It is true that Mr. Maiden is 
now bringing out a Critical Revision of the Genus 
Eucalypts," and from this, with his great reputation 
as a' practical botanist, much is expected. The first 
nrmber, on that very important species Eucalyptus 
pilularis and its allies, has already appeared, also 
part ii. on E. ohliqua and the gum-top stringy barks. 
In view of the differences in the quality of the oil 
yielded by various Eucalypts, the authors advocate 
plantations in certain circumstances of good oil yieding 
species. The lopping they suggest a forester would 
replace by copicing. It is believed that all Eucalypts 
coppice well. Mo=t of them will stand a considerable 
amount of looping, but it eventuiUv kills them. It 
is only in a few instancef that species of Eucalyptus 
are found prpdominatir.g over an area of country to 
any great exteni^, so that a particular species being 
wovked for its oil may soon be cut out in close 
pr iximity to a permanent plant. But some Eucalypts 
are very ten.icion^ 'of life, and "sick-'-rs" soon spring 
from the stumps of the trees cut down .• it is thus 
only a mattei of a few years when fresh material is 
again obtain b'e. This may be seen from the nhotoj 
graph of E SiiiitJiH^ where most of the dense grow' h 
is from "'- '^ " of this nature. We have been able 
to show, ii. several instances, that the oil obtainable 
from this yonns growth is of the same character as 
that rbt'ined f'-im the m-;n}e h-'tveo, so th-it no 
great diff 'r^n'^esi in th" quality of the oil neid he 
exp cted. BuL we thi; k it. to be a pitv that the tr-es 
should, in many instances, be felled for their leaves 
alone. By judicious lopping a fresh supply of leaves 
could more quickly be obtained, so that a permaaent 
