102 BOARD OF AGRICULTURE. 



to human research ; it is the dark field which has no success- 

 ful explorers, and is known only to the supreme Intelligence. 



The statement that the degree of sweetness in bodies is 

 due to apparently slight modification of molecular constitu- 

 tion is illustrated in a comparison of the chemical structure 

 of several allied substances. In a molecule of cane-sugar we 

 have this grouping, Ci2H220ii ; in one of glucose, CgHioOg; 

 and lactose (the sweet principle in milk) has the same con- 

 stitution. This affords a view of the molecular structure 

 of the three principal sweets, as known and distinguished, 

 the one from the other, by the distinctive degrees of sweet- 

 ness each possesses. It will be observed that there is no 

 difference whatever in the nature of the materials or atoms 

 of which they are composed : each is made up of carbon, 

 hydrogen, oxygen, and nothing else. The distinction is 

 manifestly due to the grouping of the same elements in differ- 

 ing proportions, or by different methods. We have in cane- 

 sugar a larger molecule, so to speak, it having nearly double 

 the number of atoms, as compared with grape-sugar, and it 

 holds a maximum of sweetness ; but if we had the power of 

 doubling the molecule of grape-sugar, it would not give us 

 cane-sugar. We do not at present possess the power of 

 changing the molecule of grape-sugar over into cane-sugar ; 

 and if, in the future, some fortunate chemist discovers a 

 method comparatively eas}^ and costless, he will not only 

 immortalize his name, but realize a fortune greater than that 

 possessed by any living capitalist. The molecule of milk- 

 sugar, so far as chemistry informs us, is constituted exactly 

 like that of grape-sugar : it has the same number of atoms 

 of carbon, hydrogen, and oxygen, and combined after a simi- 

 lar plan; but the two substances are decidedly unlike. They 

 differ not only jn degree of sweetness, but also in chemical 

 behavior and physical properties. Grape-sugar is not crys- 

 tallizable : milk-sugar forms microscopic crystals united in 

 nodules. The solution of the first rotates the plane of polari- 

 zation feebly towards the right ; the latter, decidedly. 



Cane-sugar, the noblest and best of all the sweets, is pre- 

 sented to us in the form of aggregated, well-defined crystals, 

 permanent under all atmospheric changes, and elegant in 

 lustre and freedom from color when well refined. It is not 

 only the sweetest of the sugars, but one of the indispensable 



