INDEX. 
with trigonometrical, by Captain Sabine, 290. — See mea- 
surement. 
Base, measurement of on the heath of Utrecht, 432— ditto, on 
ice in Fairhaven harbour, Spitzbergen, 291. 
Bauer, his micoscopical observations characterised, 2—5, — his 
microscopic drawings of the brains of man, fish, insects, &c. 
Plates I. II. — of the flippers of the Walrus, Plate IV. — of the 
Mexican Proteus, Plates XXI. XXII. XXIII. 
Bee, Humble, brain of, 6, Plate I. 
Beechey, Captain, R. N., his Survey of Fairhaven harbour, 
Spitzbergen, 29 1. 
Benzenberg, the first maker of a clock with conical pendulum, 
427. 
Birds, migration of, 11. See migration— instances of long 
flights of, 13 — care of their parents in selection of food for 
young, 20 — their expedition in pairing, examples of, 21,— 
occasional desertion of their young explained, 25, — late 
broods of, 26 — winter and summer, 27— reasons for migra- 
tion of, 27 — of passage, winter, 30 — cause of their migra- 
tion, 31 — this country their home, 31. 
Bismuth. — Its want of electro mechanical power when alloyed 
with mercury, 184 — motions of its alloy with potassium on 
mercury under water explained, 193. 
Bivalves. See shells. 
Blindness, partial, a peculiar species of, described, 224, 225, 
228 — removed by mental excitement, 225 — explained, 226 
frequent in its occurrence, 230. 
Bottoms of ships, expected to be kept clean by negative elec- 
tricity, 158- 
Bradley, Dr. His Wanstead observations used to try the truth 
of the supposed southing of the stars, 66. 
Bradley, Mr. Thomas, his drawings of Mr. South’s equatorial, 
Part iii. Plates I, II, III. 
Brain, structure of, in man, worms, insects and fishes, 1 — diffi- 
culties in its examination, 2 — microscopic drawings of, by 
Bauer, Plates I, and II— of insects described, 5. 
Brine, an excellent preservative for anatomical preparations, 
234. — Does not act on copper by reason of its containing no 
air, 245. 
Brinkley, Dr. J. on the north polar distances of the principal 
fixed stars, 50. 
