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In connoctlon with the present subject, adopting cane sugar as 

 the most important kind commercially, and as an article of food 

 from certain inherent qualities, if we examine into its sources, we 

 find them abundant, but not numerous. So far as observation 

 has extended, its production by a plant is definite ; a change of 

 locality, even when accompanied by a marked change in the habit 

 of the plant, does not alter essentially the nature of the sugar it 

 produces. Thus the cane of Louisiana rarely matures and is an 

 annual, while in the soil and climate of Cuba, it enjoys a life of 

 thirty, or even sixty years. The juice of our southern plant 

 always contains more soluble alkaline and earthy salts than is 

 found in the cane of Cuba, but its sugar is secreted as cane sugar. 

 The juice of the sugar beet, of watermelons, and a large number 

 of tropical fruits, the sap of the maple and date palm, afford cane 

 sugar. In these juices and saps, when concentrated by desicca- 

 tion in the cells of the plants, it always appeai-s in regular, bril- 

 liant crystals, of a prismatic form, clear and colorless ; distinctly 

 indicating a vital force in the plant, separating it from other 

 proximate principles and leaving it in its assigned place pure. 



The class of sugars next in importance, includes under the gen- 

 eral term Glucose, a number of sugars having varied characters, 

 which should be separately grouped. Among them are the 

 sugars of fruits, seeds, and grasses : those produced in the ani- 

 mal system, and the artificial sugars made from starch, grains, 

 and sawdust. The varieties of glucose are both solid and semi- 

 fluid. When solid they present aggregates of sub-crystalline 

 form, in which the organic tendency to rounded surfaces, is gen- 

 erally seen. The semifluid forms often manifest a disposition to 

 become solid on exposure to air, and they then experience a 

 molecular change, which produces crystals having new relations 

 to polarized light and different physical and chemical characters. 



It is unnecessary to enter more minutely at this time, into a 

 description of each variety of glucose, for the individuals of the 

 class are easily distinguished from each other, and most clearly 

 and remarkably from cane sugar. The plants producing the 

 natural glucose sugars, mature their cells as perfectly as those 

 producing cane sugar, and the secretion can be found as distinctly 

 isolated from other principles as cane sugar is ; even when the 

 glucose is semifluid. Hence we are able to determine by micro- 



