364 ON THE JUICE OF THE SUGAR-CANE. 
The composition of this cane-juice properly so called, that is 
separated from all solid substance, has been differently determined by 
those chemists who have examined it at various times, and even at the 
present day, it is not known with complete accuracy. The analyses 
made at the end of the last century were naturally imperfect in con- 
sequence of the means employed by the organic chemists of the period, 
and the data which they furnished were of a general nature, the 
precision of which was often questionable. At the commencement of 
the present century chemists of acknowledged merit, starting with the 
object of throwing new light on the colonial manufacture of sugar, the 
imperfect processes of which were recognised on all sides, proposed to 
themselves the task of determining the exact nature and the proportion 
of the elements which constituted the juice of the sugar cane. The 
difficulty of preserving this liquid in a fresh state during a long voyage, 
rendered these first essays almost fruitless. The beet plant had been 
analysed and its structure and composition were perfectly known, when 
the sugar cane still remained the object of erroneous examinations. 
It is only within the last twenty-five years that this juice has been 
studied with care and success by one of the most distinguished French 
chemists, M. Peligot. He first determined the relative quantities of 
water, sugar, and mineral and organic substances contained in the sugar 
cane, and the figures by which he has represented them, are still the 
data to be found even in the most recent works on this subject. 
This able chemist rendered a real service to all sugar manufacturers by 
discarding from the composition of the plant all those pretended sub- 
stances which were only a source of useless complexity, and by giving 
them a clear and precise demonstration of the primal material on which 
they had to operate. It is nevertheless certain that, if instead of work- 
ing in France exclusively on the juice of plants which had arrived at 
maturity, he had extended his researches in the colonies themselves, to 
the juice extracted from canes in different stages of development, he 
would have modified certain conclusions which are to be found in the 
learned memoir which he published on this subject. His opinion on 
the condition of the sugar in the cane, an opinion adopted by all 
succeeding chemists, might be perfectly correct according to the analyses 
he made ; but it does not correspond to those facts which direct and 
often repeated experiments have brought to light. Cane-juice, in fact, 
does not, as is usually admitted at the present day, contain crystallizable 
sugar only ; it contains uncrystallizable sugar, and the quantity of this 
latter substance varies in different parts of the same cane, and at 
different periods of its development. I shall dedicate a special chapter 
to the exposition of this question which is really so important to the 
colonial sugar industry, and place in evidence the fact I have just stated, 
and those conditions under the influence of which the state of the sugar 
in the cane is normally modified. I shall also examine in a special 
