ON DEXTRINE AND DIASTASE. 
269 
tion. The liquid then contains diastase and sugar, in quantity 
in proportion to the action of the diastase on the dextrine of the 
malt in the germinating process. It is then precipitated by 
alcohol, which holds the sugar in solution. This precipitate 
should be redissolved and again precipitated to obtain it pure. 
In a subsequent communication,* Payen and Persoz 
state that the soluble matter obtained according to their pro- 
cess is not a pure substance, but is constituted of dextrine, 
(properly speaking,) sugar, and a substance analogous to inulin. 
In a yet more recent communicationt Payen and Persoz 
declare that fecula is composed of amidone and teguments, 
and hence they say amidone is a natural product, and can be 
obtained by means of water alone. 
Jimidone is insipid, neuter, without color, diaphanous, 
elastic, and tenacious. It is insoluble in cold water, but swells 
exceedingly, and appears in solution; and in this state forms a 
blue color with iodine, is precipitated by tannin, infusion of 
galls, subacetate of lead, lime, and baryta. The barytic com- 
pound is soluble in an excess of either hot or cold water, and 
by precipitating the baryta with a reagent, the amidone can 
be obtained in so minute a state of division that its combina- 
tion with iodine is not precipitated by saline solutions. 
It can be obtained by boiling one part of fecula, in 100 parts 
of water, filtering through a double filter, and evaporating 
carefully to dryness; redissolving, filtering, and again evapo- 
rating to dryness; the product is amidone. 
Diastase, in its action on fecula, converts the amidone into 
gum, or dextrine and sugar. The dextrine and sugar obtain- 
ed by diastase, are not precipitated by tannin, subacetate of 
lead, lime, baryta, or infusion of galls. The sugar can be 
separated from the dextrine by alcohol of .84. It has a very 
sweet taste, and ferments with yeast, yielding alcohol and 
carbonic acid, which is not the case with dextrine. It is dex- 
trine which communicates to beer the mucilaginous property 
♦Journal de Pharmaeie, Mai, 1834 (note by Soubeiran.) 
f Annales de Chemie et de Physique, tome lvi, Aout, 1834. 
