360. QUEENSLAND AGRICULTURAL JOURNAL. [1 Nov., 1898. 
The ‘“‘density ’? or—to be more accurate—the “total soluble solids” in 
the cane-juice can, however, be easily ascertained, and this in a simple manner 
calculated to the cane. This density is usually spoken of as so many per cents. 
Brix. 
Before proceeding to say how this may be done, perhaps it will not be out 
of place to say a few words on the composition of the sugar-cane. The soluble 
solids consist of —1, Cane-sugar ; 2, sugars which reduce copper sulphate solu- 
tion, generally called ‘‘fruit sugar”; 8, organic matters, not sugars (being 
organic acids, &c.); 4, a small portion of mineral matter or ash. 
The whole stalk of cane is not homogeneous. The portions nearer the 
root-end of the cane contain more soluble solid matter and cane-sugar, and have 
a higher quotient, than portions more remote.* 
Now, as the quotient of purity decreases the further we get from the 
bottom of the cane, the factor which, multiplied by the Brix, would give us the 
per cent. cane-sugar is always different for different portions of the cane. 
Again, the “soluble solid matter” is a varying quantity from the bottom 
of the cane upwards, so that it would be a very difficult matter to choose that 
section of cane which will have the same composition as the average of all 
sections—7.¢., of the whole cane. 
With this explanation of the nature of the cane and of the difficulties in 
the way of ascertaining the density, I will proceed to the practical 
determination. 
, Under any circumstances, it is almost uscless to take portions of a 
growing cane to test, with the intention to leave the balance of that cane to 
grow. It is best to select a few stalks which, on appearance, represent the 
average of the crop of cane we wish to test. The greater the number of stalks 
we select to form one sample, the nearer ought we to arrive at the average of 
the block; but from three to eight stalks will be generally sufficient for this 
test. 
Having selected our canes, we proceed to split them longitudinally in halves. 
These halves are again split into quarters, and one quarter from each cane put 
to one side. 
We have now only to extract the juice from these quarter sections. This 
may be easily done by a small vice having a funnel or gutter arrangement 
underneath, delivering into a bottle or small glass cylinder. 
Having squeezed all the quarters, the juice in the bottle is mixed, and the 
density ascertained by a saccharometer, or Brix Spindle, the degrees and 
fractions being read off where the level of the liquid cuts the spindle (the 
temperature of the juice ought to be nearly 27 degrees C.). 
We must now assume a figure for the percentage of fibre in the cane. 
This figure varies, according to variety, age, season, crop, &c., from 6} to 13, 
but 10 per cent. may be taken where the exact figure is not known. We thus 
assume a cane to contain 10 per cent. of fibre saturated with 90 per cent. of juice, 
—H 
so that the soluble solid matter in cane = Brix of cane-juice x Oe) 
: ak 9 
or Brix of cane-juice x {00 
The Brix of the cane-juice or of the cane itself is sometimes used as a 
means of comparison between two canes. his is fairly correct only so long 
as we are comparing portions of any one particular block or of one particular 
variety, but might be most misleading if we were to compare the cane from 
one portion of a district with that of another, or were we to compare one variety 
with another. It by no means follows that the cane with the higher Brix also 
contains most cane-sugar. As already explained, the quotient of purity is the 
* The quotient of purity is the cane-sugar expressed in per cent. weight of soluble solid 
matter. It will thus be seen thatthe per cent. Brix multiplied by queen = per cent, cane 
sugar. 
