The Diffusion Process. 67 
of the contained sugar. If the* canes average 14 0/0 of 
sugar, we shall have 8.4 0/0 of first sugar. The average 
yield from mills is not more than 6 0/0, and thus the in- 
crease is 40 0/0. 
Now the total expenditure of any estate may be divi- 
ded into two parts — one a constant which must be spent 
whatever system of manufacture be adopted and what- 
ever proportion of sugar be extracted from the canes, 
the other a variable dependent on the quantity of sugar 
made. The former comprises all cultivation expenses, 
dams, trenches, punts, mules, immigration, salaries, cot- 
tages, roads, and innumerable other items, while the 
latter is incurred in the process of manufacture and is 
not necessarily proportional to, but a function of the 
quantity of sugar made. It is needless to say that the 
constant is by far the larger sum, and it is possible that 
of two processes of manufacture the more expensive 
may produce sugar at a smaller sum per hhd., by yield- 
ing a larger quantity of sugar amongst which to divide 
the large constant expenditure. For example, if sugar 
can be produced for f 80, about $60 will be the constant 
and only $20 the variable. This with the mill : now 
with diffusion the $20 increases to $24 on account of the 
coal consumption, but the 60 is decreased in the ratio of 
140 to 100, that is it becomes $43, and the cost per hhd. 
is 43 + 24 = $67 instead of $80 : and the profit is thus 
more per hhd. on a larger number of hhds. To make 
the cost by diffusion as high as that by mill, the manu- 
facturing expenses must rise to $37. 
I am open to correction as to this division of the 
$80 into $60 and $20 : I obtained my figures from a 
study of the books of an estate working under average 
I 2 
