1 Nov., 1898.] QUEENSLAND AGRICULTURAL JOURNAL, 869 
‘V. FERTILISERS CONTAINING Two oR THREE PLANT-FOOD INGREDIENTS ; AND A FEW IMPORTANT 
REFUSE MATERIALS, * 
Name of Material. Nitrogen. eee Potash. eae Water. 
Phosphate of potash ee he as: Pay 36—88 25—27 a. ne 
Nitrate of potash... Fy 2) Jes 13°5 Se: 44°0 ye <7, 
Peru guano (available) ar fr: ‘a 70 11 4:0 30:0 16°0 
Fish guano 55: a) ; 8°5 13°8 0°3 56:2 9°8 
Tankage 1 a ae ne Re 5'8 174 03 49-1 8-0 
Ashes, leaved wood... Te HY: = fe 3:5 10°0 rh ity 
5, coniferous trees F 2°6 6:0 
s» soft coal Yh ee oa ir 0:2 0:2 
», lignite... sae; rs on ae a 06 07 
»» peat 3 : 12 05 
* From the average analyses of Dr. E. vy. Wolff, “ Praktische Ditngerlehre,” 12. Edition, Berlin, Paul Parey, 
1892. This publication gives more exact figures for a great number of fertilising materials. 
THE BRAZILIAN PROCESS OF “SMOKING” RUBBER. 
A prspatcn, dated 14th May last, has been received at the Foreign Office 
from H.M. Chargé d’Affaires at Rio de Janeiro, enclosing Report of H.M. 
Acting British Consul at Para on the method at present employed on the 
Amazon River of coagulating the milk of the rubber-tree by a smoking 
rocess. 
H The report states that the juice or milk of the Hevea Braziliensis may be 
caused to coagulate by various means. By the addition of a solution of alum, 
sodium, chloride, or various other salts, or by simply allowing the milk to stand 
exposed to the air for twenty-four hours, or by artificial evaporation, the 
watery portion may be separated from the solid residue known to commerce as 
Indiarubber or Caoutchouc. To produce, however, a substance having that 
consistency and elasticity which is desirable, it is of the first importance that 
this coagulation should take place in such a way that as little water as possible 
remains in the mass. 
When the milk is allowed to coagulate by simply standing in contact with 
the air, a considerable amount of water remains in the mass—the rubber is 
flabby, inelastic, and deteriorates rapidly. It is classed together with scraps 
and débris as “sernamby,” and fetches but a low price. When alum is used, 
the result is better. In the province of Matto Grasso the milk is always 
treated with that reagent, and the rubber fetches but 3d. or 4d. per Ib. less 
than the finest Para rubber. The best rubber, known as Para fine, is produced, 
however, by rapidly evaporating the juice in the smoke produced by burning 
the nuts of the Urucury Palm (Aétalea ewcelsa). This is effected by throwing 
a quantity of the nuts on a small wood fire; a dome-shaped vessel is then 
inverted over this fire, and the smoke pours out through a hole at the top of 
the dome. A piece of wood, sometimes cut to the shape of a rough paddle or 
spoon, is dipped into the milk, and then held in the smoke until the viscous 
liquid has dried, leaving a layer of rubber on the stick. The stick is then 
dipped again into the liquid, and the process repeated until layer by layer a 
large pellet of rubber is built up. 
‘The exact action of the smoke has not yet been satisfactorily explained. 
It is probably due, however, to the acid (pyroligneous) present in the smoke. 
All the apparatus employed may be seen in the Kew Museum. But there is 
no doubt that the milk thus treated yields a very elastic, and at the same time, . 
firm rubber that is free from all tendency to flabbiness, and does not lose 
weight when stored. The smoke of an ordinary wood fire is found to produce 
what is known as “wet rubber,” that loses from 5 to 10 per cent. in weight 
whilst in the hold on the way to Europe. A considerable amount of rubber is, 
however, probably prepared by this means in localities where the Urucury 
palm is scarce. 
