September i\ 1889.] THF TROPICAL 
AGRICULTURIST. 
157 
remedy in cutaneous diseases; that of B. variegata 
is astringent, and employed by dyers and tanners; 
that of B. tomeotosa for cordage; the thick bark 
of B. racemosa is used as a slow match ; bast and 
strong ropes are made from the fibrous bark of 
several of the species, and also from those of Hibiscus 
and Sterculia. 
In Australia the bark of several trees have been 
experimented on by Baron Mueller for paper-making. 
The stringy bark of Eucalyptus obliqua is extremely 
thick and bulky, separates with the utmost facility, 
and is hence universally used for thatching rural dwell- 
ings. The supply is available by millions of tons. It 
is easily converted into packing, printing, and writing- 
paper, and may also be employed for mill and paste- 
boards. The pulp bleaches readily. The paper made 
from the bark of E . rostrata is much coarser than that 
from the stringy bark, but the pulp may be used as 
an admixture to that of packing paper and pasteboard 
or as an ingredient for blotting and filtering paper. 
The bark from several other Eucalypts also make 
good rough packing papers. 
Among savage nations, pieces of bark are piled up 
to make huts for shelter ; and the bark simply beaten 
forms rude cloth, used as petticoats and other gar- 
ments. The natives of Port Mulgrave, north-west 
coast of America, are wretchedly clothed in mats 
woven with the inner bark of Cypress, which is 
tough, flexible and very soft. 
Rolls of bark are worn in the lobe of the ear by the 
native women of the Anamallys, India. 
Curious sacks, made in Coorg from the inner bark 
of the Antiaris saceidora, are used for conveying rice 
and coffee by the villagers in Mysore. 
A kind of cloth is made in India, called Arnful, 
from the bark of Celtis orientalis. The inner bark 
consisting of numerous reticulated fibres, forms a 
kind of natural cloth used by certain tribes in Assam. 
The inner bark of some of the Conifers contains 
a fecula which, properly prepared, furnishes when 
boiled, a very edible broth. The Laplanders are very 
fond of it. When they prepare a meal of it, they 
bark the tree all around up to a certain height. 
The dried bark of the Dogwood, commonly called Red 
Willow, was used i n Lower Canada for smoking by 
the IndianB before they were supplied with tobacco, 
and many of them still, from motives of economy, mix 
t largely with their tobacco. 
From the inner bark of the Holly macerated in water 
and boiled during a long period, birdlime is procured. 
The bark of Careya arborea serves as cordage, and 
is used as a slow match for guns in the Northern 
Circars, India. 
Hemlock Spruce bark in Canada is stripped off the 
trees in long slabs, and answers as a substitute for 
boards in covering the camps or hovels used by the 
timbermen or woodcutters when engaged in the forests. 
This bark is largely employed by tanners in North 
America. 
A curious use of bark is that made in Sumatra of 
Lawang bark (Sideroxylon Zwargesi?) to clear muddy 
water, so as to render it drinkable ; it acts in a similar 
manner to the clearing nut, Strychnos potatorum. 
The bark of Quillaia saponaria, a colossal tree of 
Chili, is rich in saponine, and thus valuable for dress- 
ing wool and silk. It ia much used in France and Bel- 
gium, and occasionally appears in commerce here. 
There are many other fibrous barks which have a 
commercial value, such as that of the Mulberry (Brous- 
sonetia papyrifera), for the paper manufacture in Japan ; 
that of the Daphne longifolia and D. papyracea, 
for the .'aim' purpose in Nepal; and of Adansoniadigitata, 
which l as l> en imported from Western Africa for our 
own papermills. The curious inner bark of Lagetta lin- 
tearis is tough, but of a fine texture, consisting of 
twenty or thirty layers, each of which, on being soaked 
in water is easily separated, and extended or drawn 
out diagonally exhibits the appearance of a fine net 
lace, from which it derives the name of Lace-bark Tree. 
The ladies of Jamaica are exceedingly dextrous in ma- 
king caps, ruffles, doyleys, fans, and other fancy articles 
of the bleached bark. Cork and many other fibrous 
barks have not been noticed iu this sketch. — P. L. 
SiMMONDs. — Gardeners' Chronicle. 
GROWTH OF POTATOES. 
Tne Potato crop is of such great importance that 
anything pertaining to it is of interest. Anything, 
moreover, that can rouse us from the paralysis of 
routine and do something towards obviating the waste 
that is the consequence of our negleot and ignorance 
is worthy of attention. On this account we venture 
to call the attention of our readers to a very valu- 
able contribution to cultural chemistry that has recently 
been issued by Dr. J. H. Gilbert, fb.s., in the 
form of a lecture delivered at the Royal Agricultural 
College, Cirencester. 
The lecture embraces the results of field experiments 
at Rothamsted on the growth of Potatoes for twelve 
years in succession on the same land, with collateral 
investigations into the composition of the produce, 
made in the Rothamsted laboratory, together with 
some results by other investigators. 
The Rothamsted experiment consists of ten plots ; 
one has received no manure since the commence- 
ment, the others have received various artificial 
manures or farmyard manure. The variety of Potatoes 
grown during the first four years was the Rock ; 
subsequently the Champion was grown. 
The followiug table gives a summary of the average 
produce of Potatoes over the total period of twelve 
years, under each of the different conditions as to 
manuring. 
Manures and Produce per Acre per Annum during Twelve 
Years— 1876-1887. 
Good. 
Small. 
Diseased 
Total. 
Per cent. 
Diseased 
8 
to 
a 
a 
■4-3 
Per cent. 
0 
H 
O 
0 
EH 
0 
0 
E-i 
0 
O 
O 
Unmanured ... 
1 
13| 
0 
5 
0 
ii 
1 
19| 
3T5 
Superphosphate 
3 
5 
0 
51 
0 
2| 
3 
13J 
3-66 
Mixed mineral 
manure 
3 
n 
0 
4| 
0 
2f 
3 
15i 
8-45 
Ammonium-salts 
alone 
1 
173 
0 
61 
0 
If 
2 
5| 
4'06 
Nitrate soda alone 
2 
4§ 
0 
5i 
0 
2| 
■j 
12* 
4-93 
Ammoniumsalts 
and mixed 
minerals 
5 
181 
0 
71 
0 
8§ 
14J 
6'26 
Nitrate soda anc 
1 0 
mixed minerals 
.5 
17| 
I 0 
6| 
9i 
6 
13 
7-00 
These results show that the average produce of tubers 
over twelve years without manure is scarcely two 
tons per acre, and it was found that there was a 
considerable decline from period to period under this 
exhausting treatment. Nevertheless, this low yield 
without manure for twelve years in succession on the 
same land, is about as much as the average produce 
of Potatoes under ordinary cultivation in the United 
States, and nearly two-thirds as much as in some 
important European countries. 
By superphosphate of lime aloDe the produce is 
raised to nearly 3| tons; and by a mixed mineral 
manure containing, besides superphosphate, salts of 
potash, soda, and magnesia, to just over 3J tons, or 
very little more than by superphosphate alone. It is 
evident; therefore, that up to this amount of production, 
the character of the exhaustion induced by the growth 
of the crop on this land, which was, agriculturally 
speaking, in a somewhat exhausted condition, was 
much more that of available phosphoric acid than of 
potash, or the oth ■ L>a.ses. 
In reference to this increase in weight by mineral 
manures slone, it may be observed that the result 
is quite c insistent with that obtained with root- 
ciops, having comparatively shallow root development ; 
and in such cases the source of the nitrogen is 
chiefly the store of it in the surface soil. 
It is remarkable that there is much less increase 
of produce of Potatoes by nitrogenous manures alone 
than by minerals alone. Thus, with ammonium, salt 
there is an average produce of scarcely 2 tous, 6" cwt., 
or only about 0 owt. more than without manure ; 
and with nitrate of soda alone there ia an average 
