Indigo leaves produce two dyes--blue and yellow; but the refuse leaves,
when boiled for an hour and a half, will render the water yellow, tinged
with green. This water, kept boiling for two hours, (supplying the loss
by evaporation), will, when filtered, afford a precipitate, which, when
dried, will in colour be a dun-slate, and in quantity perhaps about
equal to the blue extract such leaves have produced. This observation,
as it can lead to no practical advantage, is made for the man of
science, rather than the man of business.--_Mr. C. Weston_--_in Brande's
Journal._

* * * * *


_Chain Bridge._


Mr. Disney has lately erected at his seat the Hyde, Ingatestone, Essex,
a suspension bridge of common chain, which is much cheaper than either
wood or brick. It is fifty feet long, and four feet wide. The whole cost
of material, and workmanship scarcely exceeded 30_l_. Upon a rough
estimate, a wooden bridge of the same span would have cost from 80_l_.
to 100_l_., and a high arch probably from 150_l_. to 200_l_. The piers
or posts supporting the chains are of oak, but should they in ten or
fifteen years decay, 10_l_. in money, and three days in time would set
it up again.--_Brande's Jour._

* * * * *