20 
The native does not attempt to deal with a mass of milk at one 
time ; he dips his spatula in- the milk and presents only a very thin 
coating to the smoke ; that first layer having solidified, the opera- 
tion is repeated; the final result is a series of thin layers, over- 
lapping one another, each of which has been penetrated through 
and through by the heat, and antiseptised by it. 
But, with all its effectiveness, the Brazilian method is slow and 
tedious; it requires an amount of sustained attention of which the 
native is not often capable ; sometimes a portion of the rubber will 
be burned ; another portion, insufficiently smoked, will readily de- 
compose, Moreover, it is quite unsuited to meet the requirements 
of an estate of some size. 
My invention is a mechanical adaptation of the Brazilian process, 
so contrived that the work is performed automatically or nearly so. 
The flow of the filtered latex can be regulated at the start of the 
operation, to the thinness of a mere film and the substance runs in 
an uninterrupted sheet on to a heated surface kept at a uniform 
and constant temperature throughout. The flow of the latex re- 
mains even until the whole milk is worked off. I have simply aimed 
at reproducing exactly the conditions under which the Brazilian 
method is conducted, while at the same time regulating it and free- 
ing it from the defects inherent to the listlessness of the native 
operator. It is not contended that the process does away with the 
proteids anymore than chemical coagulation does; but there is 
more in the action of heat thus employed, than the mere evapora- 
tion of the water of the latex. Presented in the shape of a thin 
film, the latex is seized and penetrated through and through by the 
heat, the result being a kind of “ pasteurisation’’ of the thin mass, 
which robs the proteids, now solidified and insoluble, of their septic 
properties. Hence the freedom of well cured and dried para-rubber 
from decomposition. 
This brings me to the process preconised by Dr. C. O. Weber 
of coagulation by formaldehyde. Formaldehyde or formol, sold 
in the trade under the name of formaline as a 40% solution is known 
to form compounds with albuminous substances often rendering 
them insoluble ; and, being at the same time a most powerful anti- 
septic it would appear to be a complete coagulant. And yet, even 
in this case, the removal of the proteids does not seem to be com- 
pletely accomplished, for we see that, after the coagulation has 
been effected, it is recommended, “in. order to remove all traces of 
“albumen that may be suspended, to cut the rubber into strips and 
“ subject it to a thorough washing upon an ordinary rubber wash- 
ing machine. ” 
Perhaps, then, the last word of “ proteid-free " coagulation is 
not yet found ? 
Strange to say, Mr. Hamet who experimented with every con- 
ceivable re-agent, gives fluoride of sodium as the complete coagu- 
lant to-tally destroying proteids ; and after enumerating the other 
coagulants which he employed with more, or less success, he winds 
up by saying; “other antiseptics, salol, gaiiol, formol etc. do not 
“ coagulate. ” 
