512 CHAPTER XXV 



through cheese-cloth, gg c.c. placed in a loo c.c. flask, adjusted to the mark 

 with lead acetate, filtered and polarized, and the polarization of the bagasse 

 obtained by calculation, or from a table. 



Zamaron's Method.^'' — lOO grams of finely divided bagasse are put along 

 with 200 c.c. of water in a wire basket placed in a copper container provided 

 with a draw-off cock. The bagasse and water are boiled for lo minutes 

 and the extract drawn off into a litre flask. This process is repeated seven 

 times, when rather less than i,ooo c.c. will have been obtained. Extraction 

 is now assumed complete. Lead acetate is added, the volume completed 

 to 1,000 c.c. and the polariscope reading obtained. 



Deerr's Method. ^^ — -This method employs a larger quantity of material, 

 so as to eliminate the necessity for chopping and sub-sampling with its 

 accompanying errors and consumption of time. The apparatus, Fig. 336, 

 consists of a vessel A of height twelve inches and of diameter six inches. 

 A draw-off cock, B, is fitted at the bottom and a second, C, at a height of 

 8| inches. The vessel is filled with boiling water above the height of the 

 cock C, and the surplus removed by opening this cock. A fixed quantity 

 of water is thus obtained. The bagasse is contained in the basket D, of 

 dimensions 5f inches by lof inches. This size of basket will hold 500 

 grams of loosely packed bagasse. This quantity is weighed out into the basket 

 and the latter is then placed in the container. This container is provided 

 with a wide machined, or ground, flange, on which sits the flat cover E, 

 carrying the metal reflux condenser F. Clamps or spring clips, G, make a 

 tight joint. The whole apparatus is then placed on a six-inch electric hot 

 plate or over a naked flame, and the contents allowed to boil for 45 minutes, 

 at the end of which time extraction is complete. A portion of the extract 

 is drawn off, cooled, defecated with dry lead acetate and polarized. The 

 quantity of water contained in the vessel, plus that introduced with the 

 bagasse, can be correlated with the weight of bagasse constantly used, so 

 that a half -normal extract is obtained.* The reading in the 40 cm. tube then 

 gives the polarization of the bagasse. In this scheme only one weighing 

 is required, namely, that of the basket and its contents against one fixed 

 weight, and no calculation or reference to tables is required. Bagasse 

 from the last mill of a train is sufficiently comminuted to allow of complete 

 extraction. This routine is accurate and requires less time and attention 

 than any other yet proposed. 



Determination of Sugar in Cane. — As explained in the chapter on " Con- 

 trol," this quantity is almost always obtained from combining certain of 

 the routine control observations. When a direct observation is required on 

 individual stalks, the following methods may be adopted : — 



1. Crush the stalks, halved or quartered longitudinally, in a hand mill. 

 Weigh the resulting bagasse and take the weight of juice as the difference 

 between weight of cane and bagasse. Determine the sugar in juice and in 

 bagasse and calculate back to cane. Very rough results may be obtained 

 from the analysis of the juice alone, as indicated in Chapter XXVIL 



2. Thoroughly comminute the cane and extract the sugar by aqueous 

 digestion, following one or other method indicated under " Determination 



• This is best done by fixing the weight of bagasse after ascertaining how much water is contained in the 

 apparatus. There is, of course, no reason why exactly 520.96 grams bagasse should be used, as long as a half normal 

 solution is obtained. There will be a di£ferent weight of bagasse for each apparatus, dependent on how much water 

 is held in the container. 



