298 Dr, Ives on Potatoes. 
analysis of Rinhofl, 7680 parts of: potatoes afforded 1153 parts 
of starch —fibrous matter analogous to starch 540 parts—albu- 
men 107 parts—mucilage 312 parts. The sum of these products 
amount to about one-third of the potatoes subjected to the ici 
iment, . 
Sir Humphrey pas observes, that oné-fourtle of the weight of 
potatoes at least may be considered nutritious matter. 
One-fourth of 22400, the product of an acre of ground, culti- 
vated with potatoes, is 5600. The whole weight of a crop of 
wheat calculated at 30 bushels to an acre, and at 60 pounds to the 
bushel gives, 1800. Deducting one-sixth from the wheat as mat- 
ter not nutritious, and the weight is reduced to 1500. 
The nutritious matter of the crop of potatoes to that of wheat 
is as 5600 to 1500, or as 56 to 15. 
The starch might be obtained by a very simple machine, re- 
commended by Parmentier; and in seasons when potatoes are 
abundant, the potatoes might be converted to starch, and the 
starch preserved for any length of time, and used as a substitute 
for wheaten flour. 
. ‘The machine alluded to is a cylinder of wood about three feet 
i and six inches in diameter, covered with sheet tin, punched 
outward so as to form a Bec aM and turned by a crank. 
This cylinder is placed in a Phage of pelea my vhose 
as the at is nal haga are EBL Es and the starch or fecula 
subsides to the bottom of the water. It is well known, that po 
tatoes are largely used in, England mixed with flour to form a Ve 
ry. good bread; the starch of the potato would of course answer 
much better. . 
