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scopical observations, fiidetl by chemical tests, the presence and 

 kind of sugar in the tissues, or sap of a plant, often without in- 

 curring the risk of change of properties through the chemical 

 means adopted for withdrawing the sugar. 



AVe have the authority of our associate, Mr. Sprague, for the 

 conclusion, that the Sorghum vulgare, or saccharatum, belongs to 

 the tribe including grasses, and we should therefore expect to 

 find its saccharine matter the variety of glucose called sugar of 

 grasses or fruit sugar. The unsuccessful attempts made to crys- 

 tallize sugar from the juice of the Sorghum, produced in different 

 cHmates of our country last year, indicated that it contained no 

 cane sugar, or that the presence of some detrimental matter in 

 the expressed juice, destroyed the crystallizable character of 

 cane sugar, as can be artificially done. My observations com- 

 menced after I had obtained several specimens of the Sorghum, 

 and have been continued on the semifluid sugar, likewise from 

 different parts of the United States, with uniform results. 



When a recent shaving of the partially dried pith of the 

 matured stalks of the Sorghum, is examined by the microscope, 

 we observe the sugar cells filled with semifluid sugar. After 

 exposure to air it is often possible to distinguish some crystalline 

 forms in the fluid sugar. These grains, after being washed, 

 cease to present a clear crystalline character, and have the hard- 

 ness and general appearance, of dry fruit sugar. By withdraw- 

 ing the sugar without the aid of water, it is possible to obtain it 

 colorless and neutral, as a semifluid glucose or fruit sugar, and 

 no traces of crystals or crystalline forms can be seen. The glu- 

 cose thus obtained, freely exposed to air, soon undergoes the 

 molecular change which is exhibited by sugar of grapes, and we 

 thus observe another character associating the whole product, 

 with the sugar of grasses and fruits. Leaving the physical 

 observations, and substituting the more exact processes of the 

 laboratory, I found that the semifluid sugar of the Sorghum did 

 not blacken in sulphuric acid, but was sensitive to the action of 

 alkalies, and reduced the alkaline solution of tartrate of copper, 

 thus conforming to the well-known characters of glucose. The 

 most careful trials I could make, failed in detecting cane sugar in 

 any samples of the Sorghum stalks, or in the samples of sugar, 

 including one made by Col. Peters in Georgia, prepared under 



