390 Scientific Intelligence. — Chemistry . 
contained a native race of dogs which did not bark, and were 
without hair ; and he adds, that this original race is still met 
with in some parts of America. 
36. Winter Change of Colour of the Ptarmigan. — Faber is 
of opinion that the summer plumage of the Icelandic Ptarmigan 
( Lagopus Islandorum ), on the approach of winter, changes its 
colour, and becomes white. Boie, on the contrary, from observa- 
tions made on the L. alhus , says, that this bird, on leaving its nest, 
has spotted mixed with white feathers ; but at the beginning of 
winter it moults, and then gains its white plumage. In a former 
number of this Journal we published some remarks on this sub- 
ject. 
CHEMISTRY. 
37. Salts cf Strontian and Barytes. — Moretti finds, that 
strontian and barytic earths have a stronger affinity for arsenic 
than for sulphuric acid; that the arseniates and succinates of 
strontian are rather easily soluble, while those of baryte are in- 
soluble, — a character which affords a ready means of distinguish- 
ing from each other, two earths so nearly allied together. 
38. Cooling of Glass.— BeWani finds, that after glass has been 
exposed to a great heat, on cooling, it never regains its original 
volume. 
39- Artificial Cold. — Brugnatelli informs us, the spirit of 
wine, sether, &c. mixed, in certain proportions, with snow, af- 
ford temperatures as low as those produced by sea-salt. 
40. Nature of Indian Yellow.— The Jaune Tndien, brought 
from Manilla, according to M. Mojon of Geneva, is a chromate 
of lead. 
ARTS. 
41. On the Steam-Engines in Cornwall. — We have lately 
been favoured with a recent monthly report, of Messrs Leans, 
on the quantity of work performed by fifty-three engines in lift- 
ing water, with each bushel of coals ; from which it appears 
that an engine of Mr Webb’s construction, at the Barton Mine, 
lifted 43,270,713 pounds of water, one foot high ; the load being 
18,914 pounds per each square inch, in the cylinder. We also find 
that one of Mr Woolfe’s construction, at the WheatAifred Mine, 
