94 
EDWARD TYSON REICHERT 
of its molecular characters that is of usefulness in the differentiation 
of various starches. Other methods, however, offer very satisfactory 
means of study, especially those which elicit molecular differences 
by means of peculiarities of gelatinization. These methods, all 
microscopic, have included inquiries into histological characters, 
polariscopical, iodine and aniline reactions; temperatures of gelatiniza- 
tion ; and quantitative and qualitative gelatinization reactions with a 
variety of chemical reagents which represent a wide range of difference 
in molecular composition. 
Each starch property, whether it be manifested in peculiarities in 
size, form, hilum, lamellation or fissuration, or in reactions to light, 
or in color reactions with iodine or anilines, or in gelatinization 
reactions with heat or chemical reagents, is an expression of an 
independent physico-chemical unit-character that is an index of 
specific peculiarities of intramolecular configuration, the sum of 
which is in turn an index which expresses specific peculiarities of the 
constitution of the protoplasm that synthetized the starch molecule. 
The unit-character represented by the form of the starch grain is 
independent of that of size; that of lamellation independent of that 
of fissuration, etc. This is evident in the fact that in different starches 
variations in one may not be associated with variations in another, 
and that when variations in different properties are coincidently 
observed they may be of like or unlike character. Gelatinizability is 
one of the most conspicuous properties of starch and it represents a 
primary physico-chemical unit-character, which character may be 
studied in as many quantitative and qualitative phases as there are 
kinds of starches and kinds of gelatinizing reagents, the phenomena of 
gelatinization by heat being distinguishable from those by a given 
chemical reagent, and those by one reagent from those by another, 
and those of one starch by a given reagent from those of another 
starch. The gelatinization of the starch grain is certainly not, as is 
commonly supposed, a manifestation of a simple process of imbibition 
of water, such as occurs in the swelling of particles of dry gelatin or 
albumin, but in fact a very definite chemical process corresponding 
to that which occurs in the swelling of liquid crystals, and which 
must vary in character in accordance with the reagent entering into 
the reaction. It therefore follows, as a corollary, that the property 
of gelatinizability of any specimen of starch may be expressed in as 
many independent physico-chemical unit-character-phases as there 
are reagents to elicit them. 
