54 Improvements in Physical Science (JAW, 
lages on which the experiments were made were syrup of marsh 
mallows, Iceland lichen, lintseed, and quinceseeds. (Schweigger’s 
Journal, xv. 42.) 
I ascertained long ago that gum is not precipitated from water 
by tannin. Dr. Bostock found that solutions of pure mucilage were 
not altered by infusion of nutgalls. I conceive, therefore, that the 
juices examined by Grassmann contained starch, and that the pre- 
cipitate which he obtained was a fannate of starch, or rather perhaps 
a tannate of gluten, to which its properties seem to make it ap- 
proach. 
7. Malting.—It is well known that during the process of malting 
a sweet matter is generated in grain. When barley meal is infused 
in hot water, and kept in that state for some time, the same saccha- 
rine matter, as is well known, is formed. No light has hitherto 
been thrown upon this process, though it is essential towards the 
theory of brewing and distillation. But Kirchhoff, whose views 
were naturally turned towards this subject, by his discovery of the 
method of converting starch into sugar by means of acids, has 
lately published an experiment, which constitutes an essential and 
important step in the theory of fermentation. Barley meal contains 
both gluten and starch. If pure starch be infused in hot water, it 
is not converted into sugar. Neither does gluten become saccharine 
matter when treated in the same way. But if a mixture of pure 
dried pulverized wheat gluten and potatoe starch be infused in hot 
water, the starch is converted into sugar. During the process an 
acid is evolved ; yet the gluien is little altered ; and if the liquid be 
filtered, most of it remains upon the filter. But it does not answer 
when employed a second time to convert starch into sugar. It 
appears, then, that it is the gluten which acts upon the starch, and 
converts it into sugar. By melting, the gluten undergoes a change, 
which enables it to act more powerfully in turning the starch of raw 
grain into sugar. (Schweigger’s Journal, xiv. 389.) 
8. Clarifying the Syrup of the Sugar Cane—In the Ann. de 
Chim. xcv. 232, it is stated that a Frenchman, M. Dorion, has 
pointed out a very simple mode of clarifying the syrup of the sugar- 
cane. He merely throws into the boiling juice a certain quantity of 
the bark of the pyramidal ash in powder. ‘The sugar planters of 
Guadaloupe, it is stated, have made him a present of a hundred 
thousand francs ; those of Martinique have given him an equal sum : 
and the English planters have purchased the secret at the expense of 
four huadred thousand francs, 
I have had some conversation on the subject of this statement 
with a friend of mine, a sugar planter lately come from the West 
Indies. He informs me that this plan has been tried in the West 
Indies, that it has been known for years, that he himself has em- 
ployed it; but he never heard M. Dorion’s name mentioned by any 
person. and is quite sure that the alleged purchase of the méthed 
by the English planters is not true. 
