Feb. 2, 1903.] 
THE TROPICAL AGRICU/.rURlST. 
516 
Fig. A shews the method to be followed and Fig, £ 
ihe incorrect method. 
Fig. A. Fig. B. 
The yield from 2'2 trees tapped on this principal, with 
two incisions per tree, one between the base and a 
height of 3 feet, the other on the opposite side of the 
tree at a height of 3 to 6 feet was as follows :— 
Age of trees, 9 years. Mean girth at 3 feet 
from base 4 feet 
1 inch. 
4 1 incisions made on 22 trees 29 ounces of dry 
gave rubber 
Average yield per incision '65 ,, ,, 
The central channel in each case was 2 feet 6 
inches long and the ' feeders ' 1 foot long. These 
were 1 foot ap^rt, there being three on each side of the 
vertical channel. 
Taking into consideration that the exposed surface, 
or the total length of the incision on these trees was 8 
feet () inches, as against 1 foot in the case of those trees 
tapped with a V incision, and also that a much larger 
area was operated upon the yield is at first surprisingly 
small, being less than double the amount obtained 
from those trees tapped with V incisions while eight 
times the amount of labour was entailed in making the 
extra incisions. It is evident then that some other force 
is at work vis-, the effect of wounding on the flow of 
latex, for, in this experiment the whole of the trunk 
was tapped on the same day, while iu the two previous 
experiments there were five incisions per tree and 
the operations were carried on over a period of 24 
days. This qoestion will be considered later, 
{To be continued.) 
THE FIBRE INDUSTRIES. 
The Textile Fibres of Commerce. By William 3. HannaU 
Pp. X X 236. (London : Oharles Grifhn and Co., 
Ld., 1902.) Trice 9s. net. 
The title of this work raised a hope that the author 
had seiZMl the opportunity open to any specialist of 
carrying on the critical labours of Vetillart, Wiesnet, 
Hueo >Iuller, J, Christie, Otto Witt, and the experts 
p{ tno (Jolonial ftud Indian Exhibition, now almost of 
ancient history. The opportunity is a great one; for 
the subject matter is vast, the interests involved aro 
stupendous while the first principles of the subject 
are few, vei'y few, and so are they who recognise them. 
The opportunity is one, not merely for a book enun- 
ciating in one comprehensive view the relationships 
of our highly developed textile methods to one another 
and to the properties of the ultimate spinning units, 
but for a definite forecast of the progressive future, 
which is of obvious commercial moment. 
The book before up, however, neither aims at nor 
claims to reacli the pioneer standard of technical 
literature, and must be judged accordingly. The 
author's labours have no doubt been exhaustive and 
n^inuie. But the failure to attain to the ideal stand- 
ard is self-predicted by the opening sentence of the 
introduction : — 
"The vegetable and mineral fibres of commene 
may be arranged in four groups, viz. (1) plumose fibres 
(2) stem and leaf iibres ; (3) fruit fibres (all derived from 
plants ; and (4) mineral fibres. These groups are re- 
presented by the fibres used in various important in- 
dustries, and by other vegetable fibres which at present 
are of special interest from a scieniific point of view 
only." 
This classification has no morphological basis and is 
devoid of technical significance. The sentence stands 
immediately beneath the title " The textile Fibres of 
Commerce," and the reference to these " other fibres," 
which are, in fact, from the point of view of commerce 
or industry, mere lumber, introduces us to the sup- 
posed antithesis of science to commerce, which is 
archaic, but in these days misleading, and were bettar 
left out. The introduction, in short, prepares us for 
the plan actually followed in the book, which is that 
of alphabetical sequence of the conventional or trivial 
names of the fibres ; perhaps the best in the absence 
of a positive, critical basis and consequent classifica- 
tion. The reader is thus prepared to find the book a 
non-critical compilation, and although the title sug- 
gests the subordination of the matter to commercial 
that is industrial, proportions, the expert will be 
disappointed and the lay reader will get little instruc- 
tion in the practical science of the subject. 
Of course, be it understood, a book of 230 pages, 
upon such a subject, and containing 150 illustrations, 
mostly the original work of the author and friends, 
affords much interesting reading. This interest 
belongs to the subject, which is fascinating from what- 
ever point of view it may be handled. We have no 
wish to depreciate the author's evident aim to popu- 
larise the subject ; on the contrary, we wish for the 
book a successful run, and that a second edition may 
see a considerable improvement in the matter. But 
as we take the request in the preface for " any sugges- 
tions that will enable me to add to the utility of this 
work "as an honest invitation to the critic, we feel 
we should be wanting in honesty and in a duty to 
the technical public if we shirked the task of pointing 
out by a few examples the author's want of precision 
in handling fundamental questions. We cite first the 
introductory sentence of the section " 'Vegetable 
Fibres,'' p. 3, " Physical and Chemical Properties,'' 
which reads, " The principal vegetable fibres are 
plum-Dse and bast. Both are used for spinning and 
weaving, and their prices fluctuate in accordance 
with the quality and quantity of the annual crops. The 
plumose fibies are composed of cellulose. 
Plumose and bast should not be coupled with the 
same term " fibre " unless the author intends " ulti- 
mate fibre." We take it that the spinning unit ig in- 
tended, and in the case of the bast fibres the unit is 
a more or less complex jilanicut. Fibres are not used 
for spinning ami weaving; the fibres or filaments are 
spun into yarns and the yarns woven. It is fairly 
obvious that prices vary with supply and qualitj-, but 
there is something to be said for demand. Why. how- 
ever, interject this superficial reference to the import- 
ant question of value under the heading of •' Physjc^J 
and Chemical Pioperties " '/ 
