EXPERIMENTS WITH SORGHUM IN 1891. 



USE OF ALCOHOL IN THE MANUFACTURE OF SUGAE FROM SORGHUM. 



The proposal to use alcohol in the manufacture of sugar from sor- 

 ghum is not claimed as new by the Department. Many years ago a 

 French chemist, H. Joulie, published a work on sorghum sugar, entitled 

 " Etudes et Experiences sur le Sorgho a Sucre," published in Paris in 

 1864. On pages 106 et seq he speaks of a proposed method for the 

 manufacture of sugar from sorghum by the use of alcohol, in which the 

 alcohol was applied directly to the expressed juice of the cane. 



There is no doubt of the fact that this method would work admirably, 

 and the only objection to it is in respect of the great amount of alcohol 

 which would be required. For this reason it will never be adopted in 

 practice unless alcohol should become very much cheaper than it ever 

 has been in the markets of the world. 



The method described by M. Joulie is as follows : 



As the juice comes from the mill it is immediately saturated with a little lime and 

 mixed with an equal volume of alcohol of 44 strength and left at rest. After twenty- 

 four hours the larger part of the liquid, which is perfectly clear, is decanted. The 

 rest of it is thrown upon a filter or put in filter bags, from which the liquid rapidly 

 runs and it is afterwards submitted to a press, in order to extract the last portions of 

 the alcoholic juice. The matters remaining in the filter press contain the albumen 

 and starchy matters. These bodies can be employed for feeding cattle, or, better, 

 converted into sugar and transformed into alcohol. The clear alcoholic liquid ob- 

 tained as above is submitted to distillation in order to recover the alcohol, and there 

 will be found in the kettle of the still a sirup which, when evaporated to the crys- 

 tallizing point, is scarcely at all colored and furnishes an easy and abundant crystal- 

 lization. 



From the above description it will be seen that the method proposed 

 by Joulie, which was never practiced except in the laboratory, is essen- 

 tially the same as that which was adopted by the Department of Ag- 

 riculture, with the exception of the stage of the process at which the 

 alcohol is applied. 



One special reason for the method proposed by Joulie, as urged by 

 him, was that it secured a cold defecation of the juice and thus avoided 

 the conversion of the starch which the juice contains into dextrin. 

 Joulie seemed to be unaware of the presence of gums other than dextrin 

 and starch in the sorghum juices. His idea was based upon the fact 

 that if the juice should be previously heated the starch would be 

 dered perfectly soluble. 



