( 26 ) 
It is still unfortunately a fact, however, that the 
same problems are continually being raised with 
requests for advice, which appears to indicate that 
much of the time which has been devoted by scien- 
tists to the elimination of the superficial defects 
might have been spent to better advantage in other 
directions. 
Coagulation. With the exception of native sheet, 
and possibly in the case of one or two 
large estates, all latex is coagulated with acetic acid, 
nor does it appear probable that any other coagulant 
is likely to be substituted. 
Recently the coagulation of Hevea latex has been 
made the subject of some further investigations by 
the Plant Physiologist of the Department of Agri- 
culture and the published results have led to several 
important modifications of previously established 
views as to the deleterious effects of certain chemi- 
cals as coagulants. 
The chief improvement which has taken place during 
recent years on large estates is the coagulation of 
latex in bulk in the preparation of both sheet and 
crepe rubber, which has resulted in much greater 
uniformity in the raw material. No special recom- 
mendations are necessary at the present time in 
this connection. 
MANUFACTURE of smoked sheet, due to the coagula- 
tion of latex of constant concentration in bulk in 
large divided tanks, has without doubt been consi- 
derable. The ideal type of tank, particularly in 
respect of materials used in construction, has yet 
to be found and the preparation of sheet in deep 
