Ri naa 
Scientific Intelligence. 315 
tute for galls ; but unfortunately, like the extract of quercitron, 
it affords with iron nothing but a meagre olive; and Dr. Ban- 
croft states, that in a great number of trials, he was unable, by 
the greatest accumulation, to produce any thing like a naples 
even upon wool, much less upon cotton and silk. 
A singular fact, which | observed in the course of my experi- 
ments, is worthy of notice. I had prepared for a certain pur- 
pose, solutions from the wood of the trunk of a tree, about three 
feet, and from that of a limb about three inches-in diameter. 
The same quantity of wood and of the solvent was employed 
in both cases. On adding to each the same quantity of the so- 
lution of gelatine, abundant precipitates immediately appeared, 
as usual, apparently much the same in quantity; but tomy aston- 
ishment, the size of the several congeries in each, bore a near 
proportion to that of the sticks from which they were obtained, 
not differing much from that of middling and of very small flakes 
of snow. Is not this an extraordinary fact, evincive of a com- 
plication in the arrangement of these bodies hitherto unsuspected. 
May it not at some future period, lead to a nomenclature of precip- 
itates ; affording like the crystallography of Haiiy, a pew and 
accurate mode of determining the compositions of substances; and 
Perhaps of throwing light upon the obscure subject of chemical, 
or if you please, electro-chemical affinities. The size of astick 
might probably be ascertained with almost as much precision, as 
by actual admeasurement. The solutions in this experiment, 
Were formed by maceration in cold water. When hot water 
Was employed, and the process was completed in two or three 
hours, the appearance of the precipitate was very different, 
the congeries being smaller, irregular, and not well defined. 
Ihave only to add, that having taken measures to secure the 
discovery, both in this country and in Europe, it is may wish to 
bring it into igete use as speedily as possible. 
I am, Sir, very respectfully, — 
Your most odedient servant, oP 
WILLIAM SHELDON. . 
P.S. In a short article for some future number, I may send 
you an account of the operation of the machine, and of some 
ther particulars. 
