a 
wheat not wholly changed after 10 hours. Fresh preparations of pan- 
creatic fluids from the pancreas of both the ox and swine showed that 
starches of potato, sweet potato and maize were dissolved in the order 
stated, while rice and wheat were much more resistant and were not 
finally completely dissolved. 
Pancreatin seemed less active than the other ferments, but certain of 
the starches were much more susceptible to it than others. 
To sum up briefly the result of many experiments, which have here 
been presented only in outline: 
(1) The starches of potato, sweet potato, maize, rice and wheat vary 
greatly in their susceptibility to the action of enzymic ferments. 
(2) This variation reaches such a degree that under precisely the 
same conditions certain of the starches require eighty times as long as 
others for complete solution or saccharification. 
(3) This variation is exhibited toward all of the common enzymic fer- 
ments studied, viz., diastase, ptyalin, pancreatin, in the same relative or- 
der, with slight exception. 
(4) This order, beginning with the starch which is most easily changed, 
is, for malt extract, sweet potato, potato, wheat and maize; for saliva, 
potato, sweet potato, maize, rice and wheat; for pancreatic fluids, potato, 
sweet potato, maize, with wheat and rice unchanged. 
(5) Certain of the experiments indicate that the rapidity of the change 
in particular cases is very clearly proportional to the concentration of the 
solution of the ferment. 
(6) It seems reasonable to assume that the same relative degree of 
susceptibility exhibited by these starches in the experiments described 
would still obtain when they are subjected to the action of the same 
enzymes in the processes of digestion. 
(7) The facts here presented have very important bearings upon indus- 
trial operations involving the use of starches, upon questions of physiology 
and nutrition and upon the study of the different starches from the purely 
scientific standpoint. 
In seeking for some explanation of this phenomena only two possible 
causes suggest themselves—either there is some physical difference in these 
starches by which the action of the ferments is hindered or held in check, 
or they are inherently different in their molecular structure, or in other 
words, are isomeric compounds. The first reason seems to me not a valid 
one. The starches were in each case thoroughly gelatinized by boiling 
. 
