r 115 3 



elements ; and it would be natural to conceive from 

 the composition of these bodies, as well as that of 

 starch that all three would be easily convertible one 

 into the other ; which is actually the case. 



At the time of the ripening of corn, the saccha- 

 rine matter in the grain, and that carried from the sap 

 vessels into the grain, becomes coagulated, and forms 

 starch. And in the process of malting, the converse 

 change occurs. The starch of grain is converted into 

 sugar. As there is a little absorption of oxygene., and a 

 formation of carbonic acid in this case, it is probable 

 that the starch loses a little carbon, which combines 

 with the oxygene to form carbonic acid ; and probably 

 the oxygene tends to acidify the gluten of the grain, 

 and thus breaks down the texture of the starch ; gives 

 a new arrangement to its elements, and renders it so- 

 luble in water. 



Mr. Cruikshank, by exposing syrup to a sub- 

 stance named phosphuret of lime, which has a great 

 tendency to decompose water, converted a part of the 

 sugar into a matter analogous to mucilage. And M. 

 Kirchhoff, recently, has converted starch into sugar by 

 a very simple process, that of boiling in very diluted 

 sulphuric acid. The proportions are 100 parts of 

 starch, 40O parts of water, and 1 part of sulphuric 

 acid by weight. This mixture is to be kept boiling 

 for 40 hours ; the loss of water by evaporation being 

 supplied by new quantities. The acid is to be neu- 

 tralized by lime ; and the sugar crystallized by cool- 

 ing. This experiment has been tried with success by 

 many persons. Dr. Tuthill, from a pound and a half 



