SUGAR OP STARCH, • 27^ 



All these sirups reduced to the crystalline state differ from The suDsiance 

 sugar of milk, not only in being susceptible of the alcoholic crystallized 

 fermentation, but also in being very soluble in alcohol, a property suo-m of milk, 

 that sugar of milk does not possess. Evaporated to dryness by 

 a gentle fire, a white, granular, and extremely saccharine mass 

 is the result. 



It remains to explain the manner in which sulphuric acid Theory diffi- 

 acts on starch and sugar of milk, to take from them the principle '^"'^• 

 that masks the saccharine substance, or to convert them into fer- 

 mentable saccharine matters. The author confesses, that it is 

 difficult, and out of his power, to give a clear and plausible 

 theory of this metamorphosis ; and, if he risk some notions on 

 this subject, it will be with much reserve. 



Many are disposed to adopt the opinion, that sugar exists ready Supposition 

 formed in starch, and that the sulphuric acid only dissolves or that the sugar 

 destroys the principle that holds it enchained. the\tarch '" 



It is obvious, that this reasoning is in a considerable degree objections, 

 vague ; and besides, that it is founded on no experiment, direct 

 or indirect. In this hypothesis too we must imagine a com- 

 pound altogether new, sugar combined with a substance that 

 renders it insoluble in cold v/ater ; and sugar has never yet pre- 

 sented us with such a compound. 



Others have supposed, that heat alone is capable of effecting g^pp^^j^j^^^ 

 this conversion of fecula into saccharine matter 5 a fact which, that the con- 

 if it were confirmed, might throw fresh light on the saccharine J^^^^ed by teat 

 fermentation of Fourcroy. alone. 



Accordingly starch has been boilad with water four days inxhisdis- 

 succession, till it became extremely fluid. The filtered liquor proved, 

 was evaporated, and the result was a thick mucilage, very bitter, 

 without the least taste of sugar. The starch remaining on the 

 filler resisted the action of boiling water, and exhibited a very 

 hard horny matter. 



It remains to be examined, therefore, whether the sulphuric isthe acid.or 



acid, or the starch itself, be decomposed. the starch de- 



' . . composed .' 



To judge by the letter from Petersbargh, the Russian chemists ^^^^ ^^^^^^^^^ 



seem to suppose, that a decomposition of the sulphuric acid seem to think 

 . , , the former. 



takes place. 



To account for these phenomena, we should operate in close 

 vessels. Accordingly, the author introduced into a tubulated E^'P^""^*"^ 



receiver 



