250 ANNUAL OF SCIENTIFIC DISCOVERY. 



M. Molnar mentions incidentally that he has always succeeded in purify- 

 ing spirituous liquors, and freeing them from their essential oils, by using 

 caustic potassa concurrently with recently-calcined wood charcoal. Dingier' s 

 Polytechn. Journal. 



ON THE CHEMICAL CHANGES OF THE GLUCOSE OF THE SORGHUM. 



At a recent meeting of the Boston Society of Natural History, Dr. A. A. 

 Ha} 7 es read the following paper " On a chemical change which takes place 

 in the Glucose of the Sorghum : " 



In a paper communicated some months since, I alluded to the fact, that 

 the glucose of the sorghum cultivated in New England, like fluid fruit 

 sugar, passes to the condition of dry, or crystalline fruit sugar. The subse- 

 quent more careful investigation of this change, proceeding indeed during 

 many months, has resulted finally in the production of pure glucose of sugar, 

 having the higher grade of a variety of beet-root, or cane sugar. 



In the account which follows, the experiments were made on the glucose 

 of that variety of sorghum which has dark purple seed coverings, the 

 variety generally cultivated in the Northern States. 



When we extract the saccharine matter of the stalk of the sorghum, 

 either by expression, or through the aid of water, and purify the solution 

 by means of animal charcoal, we obtain glucose, holding in solution some 

 salts of potash, lime, and soda. This glucose does not afford crystals by 

 evaporation in desiccated air, nor does alcohol, saturated with cane sugar, 

 leave undissolved any sugar. 



The perfectly formed cells of the plant, triturated with animal charcoal, 

 afford to boiling alcohol the same substance. The dry glucose is abundantly 

 soluble in alcohol of 86 per cent., and the dense syrup of the same dissolves 

 without limit in it. After exposure in warm air, crystalline concretions, 

 resembling dry grape sugar, form in isolated masses. Analysis shows a 

 large proportion of saline matter, composed of phosphoric acid, chlorine, 

 sulphuric acid, acetic acid and potash, soda, lime, and oxide of iron. This 

 saline matter forms a compound with the glucose, ami thus makes up the 

 crystalline grains, which first appear in the dense syrup. These are constant 

 results, in treating the plant which has been cultivated the two past seasons, 

 and they present no remarkable feature, in comparison with those obtained 

 on glucose from other sources. 



After the lapse of several weeks, however, the pure glucose which has 

 been withdrawn from the foreign aggregates exhibits the production of 

 crystalline points, which, becoming numerous, soon assume the forms of 

 regular crystals. These crystals increase in volume, but while forming in the 

 glucose they present skeletons, rather than solid crystals, of a pure substance, 

 and are often grouped. Crude syrup, remaining after the concentration of 

 the juice by rapid boiling, undergoes the same modification, and crystallized 

 sugar slowly separates from samples which did not originally contain any. 



Slips of the pith of the plant, which had been carefully examined under 

 the microscope, without any traces of crystals being found, after some 

 mouths, show their cells filled with voluminuous, dry crystals. Repeated 

 trials prove that the chemical change, resulting in the production of the 

 crystals, from glucose, is not dependent on exposure to air and loss of water, 

 but it takes place when the syrup is kept closed in bottles. 



As the glucose is abundantly soluble in alcohol of 90 per cent., this agent 



