Report of Society's Meetings. 145 
of dire6l determination, but of mere calculations from data 
of most doubtful accuracy. In fact, these analyses of 
cane that pass muster even at the present day, and are 
copied from one text book into another, were made at a 
time when no exact methods of determining sugar were 
known. They were made at, or prior to, a time when 
large rewards were being offered by Governments and 
scientific societies for the discovery of a method by 
which sugar could be estimated with some pretence to 
precision.* Before Trommer's copper test for glucose 
had been made quantitative by Barreswill (1884) and 
Fehling, and before Soleil and Clerget, the pioneers 
of optical saccharometry, had practically utilised Biot's 
discovery of the circular polarization effected by sugar 
solutions, and had constructed and applied the polarising 
saccharometer. 
In fact, the analyses were performed in a very pri- 
mitive, not to say a rude manner. The total solids in 
the juice were determined by evaporation of the water; 
then the non-saccharine organic matter by precipitation 
with acetate of lead ; and finally the salts or mineral 
matter, by drying and burning a portion of the juice. 
The two latter being deducted from the total solids, the 
remainder was called sugar, and this completed the ex- 
amination of the juice. A weighed portion of the canes 
in slices was then dried, and the loss in weight repre- 
senting water, noted; the soluble matter in the cane 
was then washed out with water, and the residue, being 
dried and weighed, gave the amount of fibre. The 
* The conditions of the prize offered by the Societe (V Encouragement 
of Paris called only for a process that would determine within two per 
cent. (!) the richness of saccharine substances. 
