314 _ Scientific Intelligence. 
dish brown, The lake of the chesnut is indeed a blue, and not 
to be distinguished by the eye from indigo; but when diffused on 
paper, this same substance becomes of am intense shining black. 
In dyeing, little difference is observable between the chesnut and 
galls,.and sumach, except that the former has a rather greater : 
affinity for wool, &c. than the latter, and of course requires 
less boiling. Its permanency has been completely tested by 
long exposure tothe sunand the weather; but no doubt can ex- 
ist on this head, if the position of Berthollet be true, that perma- 
nent blacks are formed only by the combination of iron and tannin. 
. To prepare the chesnut wood for the purposes of tanning, # 
mode has been devised for reducing it to a suitable degree of. 
fineness. This method consists in the application of knives, 
either in the direction of, er transversely to the grain, by a rota- 
tory motion. This mode obviously involves the greatest possi- 
ble economy of moving power. Messrs. B. and M. Stebbins, of 
West-Springfield, who are making arrangements for going large- 
ly into the exportation of the article, have in construction a ma- 
chine upon this plan. 
As might be expected, the inspissated aqueous extract of the 
chesnut, bears a near resemblance in many particulars, to 6 
techu. Professor Dewey, of Williams’ College, who at my re- 
quest, has gone through an extensive and elaborate course of 
experiments, informed me that he obtained a quarter more of 
cept that the former is more pungent. It leaves upoP the 
_ tongue, th P t and refreshing sweetness, for which 
the other is so much prized in the east; where it is used 98 wad 
article of luxury, with betel nut. Might not the extract be ad- 
vantagecany substituted for catechu, in the celebrated life pre- 
serving composition of Dr. Pearson; the object being te cone” 
trate the greatest possible quantity of nutritious and tonic sub- 
stances in the smallest weight. 
The coloring properties of the two substances, are entirely 
different. After the discovery, twelve or fifteen years since, ¥ 
the composition of the terra japonica, attempts were made in 
England to introduce it into the materia tingentia, 4% @ 
gubsti- 
