134 ' The Philippine Journal of Science 1920 
purity cane no loss might be entailed ; but, should he insist upon 
its being milled on the contract basis, it must be ground, since 
the usual contract contains no proviso for the refusal of poor 
cane. The manufacturer must proceed with the work, even 
though he knows the cane to be poor. Obviously it would be 
to the advantage of all if a fair standard of purity were es- 
tablished, to serve as a basis for determining whether cane may 
be considered millable or not. 
Cane, to be considered millable from the standpoint of the 
central, should be of such sucrose content and purity that 
the central can work it into sugar and molasses with the equip- 
ment on hand, without being compelled to resort to remelting, 
special processes, or the purchase of extra machinery. From 
juices extracted from millable cane it should be possible to pro- 
duce 96° sugar or better, and a molasses showing an average 
purity. Obviously cane showing a purity of only 60 per cent 
for the mixed juice will not, by itself, produce in one operation 
a standard 96° sugar; the sugar resulting after leaving the 
crystallizer and the centrifugals will have to be remelted or, 
if a good grade is obtained, it will at least have to be mixed 
with a higher-grade molasses for further conversion into a stand- 
ard centrifugal sugar. This procedure not only complicates 
the work, but also increases the cost of manufacture and, there- 
fore, reduces the profits to the central. 
In determining a fair standard for millable cane the purity 
of the juice is not the sole factor to be taken into consideration. 
For example, a juice with a Brix of 10° and a purity of 80 
per cent will give a rendement of 5.76 per cent, while a juice 
with a Brix of 15° and the same purity, will give a rendement of 
8.66 per cent. Both juices mentioned are equally millable. 
However, the cost of transportation of the cane per ton of sugar 
is much greater in the first case than in the second, and the 
steam consumption for evaporation of the first juice is consid- 
erably greater. Therefore, there should be adopted also a min- 
imum for the degrees Brix. 
A modem factory making a 96° sugar will adopt the three- 
boiling system, this being the most economical and the easiest. 
The purities maintained will be: for the first boiling, 80 per 
cent; for the second, 70; and for the third, 60. These purities 
are obtained by boiling straight sirup to grain, and then adding 
molasses from former strikes so as to obtain the required pu- 
rities in the finished massecuites. The purity of the sirup 
should not fall below 70 per cent. I am fully aware that, as 
