582 
washing is continued till the water comes off perfectly pure, the 
rubber will be of first class quality and keep indefinitely. When it is 
considered that it has been washed -enough warm water is poured 
on the creamy layer, and coagulation or as the editor of the Journal 
prefers to call it coalescence is produced. A workman inserts a 
wooden stirrer ajid draws out a layer of rubber which he takes off 
by hand and forms into a lump which is flattened between the cy- 
linders of a small roller. The plates thus obtained are thrown into 
a large water tank and stop there twenty-four hours, being after- 
wards dried in the sun. If the washing is complete the rubber 
° remains quite white, but if small quantities of oxidizable matter 
remain it becomes yellowish, but nevertheless it makes a first 
class quality of rubber In order to prepare a good lot at the same 
time, this preparation is only made once in eight days. The daily 
collections of latex are mixed together and to avoid their sponta- 
neous coagulation which often happens in 24 hours, the latex is 
kept in a refrigerator. Here at a very low temperature there is 
no coagulation nor alteration of any kind, and the latex remains un- 
changed indefinitely. 
M. Rodriguez the proprietor of the Aguna plantation, makes 
on the spot waterproof materials for his own use. The cloth is 
painted with a brush with successive layers of fresh latex mixed 
with sulphate of iron and flowers of sulphur. Then it is exposed 
to the sun for a sufficiently long time. 
It becomes completely black and dry and the mixture adheres 
very closely to the cloth without interfering with iti flexibility, a 
good deal of washing in plenty of water completes tne operation. 
The sulphur is added to prevent the cloth remaining sticky. M. 
Rodrigues imagines that a kind of vulcanization takes place, any 
way the result is very satisfactory. By mixing a little liquid latex 
with ordinary paint, he has also found that a very brilliant and dur- 
able impervious surface is produced on canvas, wood or iron. 
TRANSLATION OF A LETTER BY RAJA BOT, SELANGOR, 
GIVING HIS VIEW ON THE SUBJECT OF 
Extending the area of Rice Cultivation. 
To His Highness SULTAN Suleiman of Selangor, and to the 
Resident-General W. H. Treacher, Esq., C. m. g. 
I crave permission to approach your Highness and your Honour 
with this letter, and beg you to weigh fully the contents thereof. 
If there is any truth in my words please make use of them ; if not 
you may ignore them. 
I was first manifested to this world on Friday, the 25th of the 
month Zil Hayjah, in the year 1263 (A. H.) At eight years of age I 
had read the koran and not long afterwards was judged proficient 
therein. On the 9th day of Ramathan, 1271 (A. H.) my father, Raja 
Snay, son of Sultan Muhammad, died, and was buried at Lukut. 
Just about that time I began to understand and to take some 
