41 
26 
Zacualpa. This sulphurizing the latex is, of course, easily feasible, 
but beyond its preserving action on the crude rubber theie is very 
little to recommend it to the planter. From the manufacturer s 
point of view, however, a very strong objection will be raised, and 
it seems to me this cannot be overlooked. In -whatever way we add 
solid sulphur to the latex, the quantity will vary on different planta- 
tions and no uniformity can be achieved. This method further 
lends itself to adulteration, which the rubber buyers always seem 
to be afraid of., It would in every case be necessary tor the 
manufacturer to analyse his crude rubber for sulphur, and in most 
instances he would have to desulphurize the rubber before vulcaniz- 
ing As the rubber must h e masticated before it is mixed with 
the various ingredients necessary in manufacturing different 
articles, there is nothing to be gained in the way of preserving the 
' “ nerve ” of the rubber. 
I mentioned above the disinfecting and preserving action sul- 
phur would have on the crude rubber. My series of experiments 
on sulphurizing latex and preparing rubber from thus treated 
material consisted of 63 different experiments:; each varying 
from the others in some more or less important respect. 1 made 
good samples of rubber, and bad ones, from the sulphurized latex. 
In most cases there was no development of bacteria in the lubber, 
even though the samples of rubber were exposed in the culture 
jars to an atmosphere full of spores of moulds and decaying latex 
was poured over the rubber. Inoculation of bacteria cultures 
c made of different forms occurring in “ tacky ” rubber was tried but 
failed to develop on samples where a thorough admixture ot latex 
and sulphur has been • accomplished. The preserving power ot 
sulphur mixed into the latex seems undoubted. 
I have tried many various methods of smoking the Castilla 
rubber, and of coagulating by means of smoke. The most suc- 
cessful one is, I believe, the following. The fumes of burning 
sulphur were pressed into the^latex for varying periods, and it was 
found that this assisted considerably the coagulation. I then 
mixed fumes of burning sulphur with the smoke of creosoted wood, 
pressed this mixture through a cooling apparatus to slightly bring 
down the temperature, and thoroughly fumigated the latex. 1 ms 
coagulated quickly and gave a grayish rubber, perfectly trans- 
parent, with a high degree' of tensile strength. It has not 
deteriorated in the six months that have passed since the experi- 
ment wa? made. Whether this method will be incorporated in the 
manufacturing process on La Zacualpa depends on further experi- 
ments. The present results indicate that there is a possibility in 
this direction. 
Rubber Experiments. 
Before ending this brief description of conditions on La Zacu- 
alpa, I wish to mention a few words about the experiments which 
are being conducted at La Zacualpa Botanical Station and Rubber 
Laboratory. This institution began its work on December ist, 
1005 Its purpose is the scientific investigation of the various 
problems connected with rubber culture. In the short time of its 
existence the station has not been able to accomplish very much 
