ON DEXTRINE AND DIASTASE. 
273 
identical with tegumentary amidin. He also observes that 
fecula is composed of — 
Tegumentary amidin, 2.2 } 
Soluble amidin, 38.68 > 100.00 
Amidine, 59.12) 
Guerin also queries whether his tegumentary amidin is iden- 
tical with lignin, and owes its property of coloring blue with 
iodine to a small quantity of adhering amidine, or whether it 
is merely isomeric with that substance. 
We have now gone over most of the writers on the subject 
before us, and have unfolded their several views as concisely 
as possible. It now remains to give the ideas of M. Raspail, 
the latest writer on the subject, whose work has come to hand. 
He differs widely in his opinions from most of those which 
we have detailed, and it is proper that they also should be ex- 
posed ; avoiding, however, the many sarcastic remarks with 
which his pages are interspersed, we shall endeavor to place 
his views in as clear a light as possible. 
According to this writer, fecula consists of soluble matter 
and teguments; the latter enveloping the former; the one en- 
tirely insoluble in water, and the latter very soluble in that 
fluid. To the soluble matter he gave the name of soluble 
substance of fecula; and to the insoluble portion, teguments; 
stating, at the same time, that the latter consisted of the outer 
envelope, and an interior tissue, which, from its extreme te- 
nuity, was capable of being diffused through the solution of the 
soluble substance, so as to appear in solution, though it really 
was not, and in time was wholly deposited. 
He queries what is the dextrine of Biot?* and answers 
that it is the soluble substance of fecula. 
He again queries what is the diastase of Payen and Per- 
soz? after speaking of the unhappy application of this word 
to the substance in question, which signifies division, or sepa- 
ration, and is already used in chirurgy to signify luxation, 
he remarks, that the diastase of these chemists is distinguished 
*Nouveau Sysleme de Chimie Organique, tome i, art. Amidon. 
vol. v. — no. iv. 35 
