Ponp.—On the Sugar Values of Beet-roots. 369 
out, the root being richer in sugar in the lower than in the upper portion. 
Having thus obtained a fair average of the root, I have accurately weighed 
and then pulped the assay portion in a mortar with distilled water, and 
inverted the sugar in the ordinary manner with dilute sulphuric acid, 
making my quantity up to a known amount, from which I have charged 
the burette in the ordinary way. 
Fearful of the conversion of the woody fibre into glucose, and a conse- 
quent false increase of the results, I have frequently checked this process 
by filtering off the diffused juice from the pulp, well washing the latter, and 
then inverting the sugar contained, but in all these cases the pulp still 
retains a small amount of saccharine matter, but the difference between 
these two methods is so small as not to cause much disparity, and here I 
will give one experiment to show the difference. A root of the Red-top 
Imperial, weighing 23 lbs., was taken, and two cores from the puncture tube 
fairly chosen, to the weight of 2 grammes each, pulped, and the one 
inverted with the pulp, the second filtered, the pulp washed and the filtrate 
mverted ; the percentage of sugar being 9-82 in the first portion, and 9°50 
inthe second. The difference I attribute to the sugar still left in the pulp. 
The methods by which I have determined the percentages of sugar, have 
been with Fehling’s copper solution, and Knapp’s mercuric cyanide solution, 
both volumetric analyses, the former being in my opinion the most accurate. 
To ensure precision, I have frequently inverted pure anhydrous cane sugar, 
and estimated my standard solutions with it, and therefore feel justified in 
Saying that the analyses given by me in this paper are reliable. 
In addition to the chemical analysis we have the specific gravity, this 
being a very reliable guide to the value of sugar present, and this I have 
obtained after expression of the juice on several occasions by means of the 
balance. Before concluding this portion of my paper on the chemical 
Manipulations, it will be interesting in a few cases to note the relative pro- 
Portions between the chemical values and the specific gravities. 
The root already mentioned as having been received from Mr. Walker, 
Cambridge, and which I estimated to contain 15 per cent. of sugar, was 
Stated until it had lost weight equal to 200 grammes, the juice from which 
being expressed equalled 128 c.c., added water to the pulp and macerated, 
Pressed to near dryness and made up the amount with water to 200c.c. 
Found the specific gravity of the pure juice before adding water to be 
108087, and the percentage of cane sugar in the 200 c.c. to be 14°35, the 
difference being the amount of sugar still retained by the pulp. Again a 
*oot from Mr. O'Neill was grated, 11b. of which yielded 14}0zs., weight of 
itiee, and 1g0z. pulp. The specific gravity equalled 1/0528, and the per- 
“entage of sugar in the juice was 11-4. 
