July i, 1881.] 
THE TROPICAL AGRICULTURIST. 
i6r 
propiolic acid), the courless substance which on treat- | 
ment with a reducing agent yields indigo-blue, is already 
in the hands of the Manchester calico printers, and is | 
furnished by the Baden Company for alkali awl analine 
colours at the price of 6s. per pound for a paste contain- 
ing 25 per cent, of dry acid. With regard to the 
nature of tbe competition between the artificial and the 
natural colouring matters,. in the first place, the present 
price at which the manufacturers are to sell their 
propionic acid is 50s. per kilo. But 100 parts of the 
can only yield, according to theory, 0S.5S parts of 
indigo-blue, so that the price of the artificial (being 
738. per kilo.) is more than twice that of the pure 
natural colour. Hence competition with the natural 
dye-stuff is not to be thought of until the makers 
can reduce the price of dry propiolic acid to 20s per 
kilo, and also obtain a theoretical yield from their 
acid. This may, or it may not, be some day accom- 
plished, but at present it will not pay to produce 
indigo from nitrophcnyl-propiolic acid. Nevertheless 
a huge Held lies open in the immediate future for 
turning Baeyer's discovery to practical account. It is 
well-known that a great loss of colouring matter occurs 
in all the processes now in use for either dyeing or 
printing with indigo. A large percentage of indigo is 
lost in the " cold vats " in the sediment. Another 
portion is washed off and wasted after the numerous 
dippings, while, in order to produce a pattern, much 
indigo must be destroyed betore it has entered into 
the fibre of the cloth. Moreover, the back of the 
piece is uselessly loaded with colour. The proper way 
of lo 'king at this question at present is to cousider 
suited for the heavier labour of a plantation, there- 
is ample scope for English labour, and still more 
ortho-nitro-phenyl- 
d natural 
as two distinct products not comparable with each 
other, inasmuch as the one can be put to uses for 
which the other is unfitted, and there is surely scope 
enough for both. Still, looking at the improvement 
which will. every day be made in Hie manufacturing 
details, he must be a bold man who would assert 
the impossibity of competition with indigo in all its 
applications, for we must remember thai we are only 
at the beginning of these researches in the indigo 
field.— Overland Mail. 
L1BERIAN COFFEE IN AUSTRALIA. 
By degrees 
as a field for 
and sugar, s 
ai" kill:' gr; 
grown almost aloi 
paratively short i 
and cattle rearing, 
coffee, made by ft 
tion at Maragen, 
proved very succe: 
supplied from K.e 
ripened ' their mai< 
fortunate and em 
promising for the 
Northern Australi 
planting or sugar- 
1 1 
Sir J. D. Hooker, have just 
p, and are described by the 
pg planter as looking very 
e. The vast , resources of 
such an industry as coffee- 
g ought to be much better 
they are. The soil is fertile, 
ind the climate better adapted to the European con- 
stitution than that of many other tropical countries 
whose resources have been hitherto more fully recog- 
nised. Land equal to any in the tropical world can 
bo taken up for 5n an acre, and the payment can 
bn spread over a period of ten years. Here is a 
chance for young Englishmen with a little capital, 
Bud leisure to study the requirements of the country 
and 'In' beat methods of tropical agriculture before 
rushing into expenditure. Some of the surplus popu- 
lation of In lia should find congenial occupation and 
climate in Northern Australia, where they would find 
a heartier welcome than tin- " heathen Chinee" ; but 
Wl.ilr Coolie labour Would plobahl\ be found best 
41 
,i Tndi 
japital; in tropical Australia. — Colonic* 
" New Commercial Plants and Drugs. " — We 
have received from Mr. Thos. Christy No. 4 of 
this series of pamphlets. This nunibe. - deals with 
Ceara Rubber, Maugabcira rubber, Urostigma Vogelii, 
apocynaceous rubber, Landolphias, &c, and a number 
of drugs some new to Europe. Regarding the Uro- 
stigma Vogelii Mr. Christysays :— " As Dr. Trimen has 
some of these plants growing in Ceylon, I look for- 
ward with iuterc-t to his accounts of the india rubber 
.vhich they yield, and hope in a future number to 
be able to give some account of their value from an 
agricultural point of view." Apocynaceous rubber is 
thus described :— " A plant yielding rubber which grows 
in East Africa, and the seeds of which one of my 
correspondents sent me home among a collection of 
plants, together with a piece of very fine irjdii- 
rubber obtained from it, appears to belong to a 
hitherto undescribed species. 1 planted the seeds cor- 
responding to the rubber, and find it to be a ceeper* 
but on account of the flower not being perfect, and 
there being no plant that exactly correspond^ » to 
it in tho Herbarium at Kew or at the British Mu-eum, 
it is imposible to give it a name until it has flowered. 
Some of these plants have been sent to Ceylon, to 
the Botanical Gardens and to merchants." Of the 
papaw we read : — '■ Dr. Bouchut (Archives Gen. dp, 
Med,, July 1880) has found that both the diluted 
juice aud Papaine, have tbe property of digesting 
living, tissues, normal or pathological, such a^ a eno- 
mata and cancers, and converting them into pept«ues 
in exactly the same way as dead ones. It seems prob- 
able that this knowledge may be turned to accouut 
in the treatment of cancer and oilier abnormal growths. 
The false membranes of croup and diptheria removed 
by tracheotomy, and also worms, such as tape worm, 
aud round worms, are attacked and digested in a 
few hours by the Papaw juice." In the preface Mr. 
Christy says :— " The Ceara rubber has been so highly 
spoken of as to cause a great demand for the seed. The 
supply is short for the time being, owing to the 
trees being killed by the drought over a large radius 
of country iu Brazil. According to Hecht, Levis 
and Kahn's report for 1879. 25 tons of Ceara 
Rubber and 900 cons of African Landolphia Rubber 
were imported some 350 ions of Assam [Ficus Elastica), 
250 tons of Borneo ( Willughbeia), 500 tons of Mozam- 
bique (Landolphia) Rubber. By this it will be seen 
that next to the Para Rubber, of which 6,651 tons 
were imported, tbe Landolphia Rubber occupies the 
first place, while the Ceara, owing, no doubt, to the 
severe drought which has been prevailing in that 
district, only returns about 25 tons as imported into 
England ; but I have no doubt that if this variety 
is well cultivated iu Ceylon and other rubber grow- 
ing countries, that its returns will rival with those 
of others. The Maugabeira will be another favorite 
variety of rubber teee, and it has not suffered by the 
drought. • The fruit carries well, even to Eiii'°pe, go 
it will be an acquisition in Ceylon. The etnulWGaved 
rubber plant I received from East Africa, and which 
is growing in Ceylon, is easily propagated by seed 
and cuttings ; it ha- not been named, but the rub'ier 
was so much admired lor its transpaiciit ap t.ira cc, 
that I prefered to allow Ui6 plants to go out name- 
less than keep them for the name. I have published 
the drawing as a guide to others to search lo plants 
of a similar kinds. From the samples ,.t stems aud 
pieces of trees in my possession, I am convinced 
that there are many other rubber plants that will 
repay the trouble of cultivation. " 
| • Wheu primed it forms a bush or tree. 
