October 23, 1H^6.] 



SCIENCE. 



361 



SORGHUM SUGAR. 



EXPEEIMENTS are being carried on at Fort Scott, 

 Kan., this fall, under the direction of the U. S. 

 department of agriculture, in the application of 

 the diffusion process for the extraction of the 

 sugar from sorghum cane. This is a continua- 

 tion of the work at Ottawa, Kan., last year, the 

 results of which are embodied in Bulletin No. 7, 

 chemical division, department of agriculture. 

 At Ottawa experiments were made in connection 

 with a sugar-factory, which employed a mill to 

 work up most of their crop. This year the Par- 

 kinson sugar company of Fort Scott, relying upon 

 the results obtained there, erected no crushing 

 machinery whatever, depending entirely upon the 

 diffusion battery to extract the sugar from their 

 cane-crop of over eight hundred acres. 



The crop this year showed the remarkable 

 power of resistance to drought of the sorghum- 

 plant, the patches of which constituted about the 

 only oases of green in an otherwise dry and 

 withered -up vegetation. 



The factory has been in operation since about 

 the 1st of September ; and while the results do 

 not, perhaps, fulfil the anticipations of the more 

 ardent advocates of diffusion, still they are in 

 many respects most satisfactory, and full of 

 promise for the future success of the sugar in- 

 dustry. 



It is turning out a very fine article of sugar, in 

 large quantities, fully as good as to crystallization, 

 color, and taste, as any made by mill extraction ; 

 while the analysis of the exhausted chips shows 

 an almost complete extraction of all the sugar 

 content of the cane, — something which is im- 

 possible to obtain by pressure extraction, however 

 thoroughly applied. 



The pi'incipal difficulties which were encoun- 

 tered have been, first, the proper chipping of the 

 cane, or preparing it for diffusion ; and, second, 

 the treatment of the juice obtained. These are 

 both points in which the previous applications of 

 diffusion, viz., on beets, offered but little guidance, 

 the nature of the substance used being so very 

 dissimilar. The sorghum cane is fed directly to 

 the cutters, with the leaves and sheaths still on 

 (it is too expensive to strip it) ; and while these 

 are partially taken out afterwards by means of 

 blowers and fans, stiU a large percentage find 

 their way into the cells with the chips of cane, 

 and from these a great many colloid matters are 

 extracted by the juice which interfere material- 

 ly with its proper clarification and the crystal- 

 lization of the sugar. The solution of this diffi- 

 culty will undoubtedly be found in a more perfect 

 mechanical cleaning of the chips, or by the in- 

 vention of machinery by which the stripping of 



the cane can be accomplished more cheaply than 

 by hand-labor. 



The problem of the proper treatment of the 

 juice calls for the greatest amount of chemical 

 ingenuity and invention. The juice obtained by 

 diffusion is niuch more impure and difficult to 

 treat than that obtained by a mill, partly on ac- 

 count of the presence of the leaves, etc., as 

 already mentioned, and partly because the tissue 

 of the cane does not seem to be as good a medium 

 for osmosis as that of the beet. 



The process sought to be applied to this juice 

 at Fort Scott is that of carbonatation as used upon 

 beet-juice. The details of this process are well 

 known to those versed in sugar methods : milk of 

 lime is added in large excess to the juice, and is 

 then precipitated as carbonate by treating with 

 carbonic-acid gas. The glucose, liovvever, which 

 is a constant constituent of sorghum juice, and of 

 which the beet contains no trace, unites with the 

 lime to form a dark-colored, bitter-tasting com- 

 pound, which no amount of carbonating can break 

 up. This difficulty has been to a large extent sur- 

 mounted by performing the carbonatation at a 

 low temperature, and heating only after the excess 

 of lime has been entirely neutralized by the car- 

 bonic-acid gas. A novel modification of this pro- 

 cess has also been attempted by adding freshly 

 precipitated carbonate of lime directly to the 

 juice, heating, and sending directly to the filter- 

 presses, thus avoiding the direct contact of the 

 juice with caustic lime. The indications from 

 the present results are most hopeful, — that, with 

 the expenditure of a small fraction of the money 

 and brains that have been required to develop the 

 sugar of the beet, the sorghum-sugar industry 

 will take a leading place among American in- 

 dustries, and enable Uncle Sam to accomplish a 

 long-cherished hope, viz., of making his own 

 sweets. 



It is the intention of the department of agri- 

 culture, at the conclusion of the sorghum season, 

 to make some trials of the Kansas machinery 

 upon Louisiana cane, getting it in by rail, pend- 

 ing the trial of next year, when it is expected to 

 erect a diffusion plant in that state. With the 

 l^roper co-operation of the railroads and of the 

 southern planters, this can undoubtedly be carried 

 out ; and the results will be most valuable. The 

 sugar-planters of Louisiana have been watching 

 with the keenest interest the experiments in 

 Kansas, several of their representative men being 

 on the ground. They reason that its success upon 

 sorghum cane will augur its success upon their 

 own plant, many of the difficulties attendant upon 

 its application to the former not holding good 

 with respect to the latter. 



