( 690 ) 
[November, 
NOTES. 
A new Camera Lucida has been invented by Dr. Schroder, 
possessing many advantages over the well-known contrivance of 
Dr. Wollaston. The pencil emerging from the eye-piece of the 
microscope is reflected twice, as in the old instrument, but the 
view of the paper and pencil is obtained by means of another 
prism placed under the first; the pencil from the microscope is 
totally reflected, and cannot pass through the film of air between 
the prisms, and the paper is seen diredtly through the two 
prisms, which offer no more obstruction to the view than a thick 
piece of plate glass. The position of the image does not shift 
when the eye is moved, and the painful strain caused by the 
bisection of the pupil in the Wollaston instrument is entirely 
avoided. Drawings can be taken either with the body of the 
microscope at the usual inclination of 45% or in a vertical posi- 
tion, both more comfortable in every respecft than the old hori- 
zontal one, and preventing disturbance of the illuminating 
arrangement by having to shift everything when a drawing is 
required. 
M. Miquel (Semaine Medicale) has examined the number of 
bacfteria in portions of air of 10 cubic metres each, taken in 
quick succession. At heights of 2000 to 4000 metres in the 
Alps the number was o ; on lake Thun (560 metres above sea- 
level), 8; near the Hotel Bellerne (500 metres), 21 ; in a room 
in the Hotel, 600 ; in the Parc de Montsouris, 7,600 ; and in the 
Rue de Rivoli, Paris, 55,000. Cold has little effect upon 
bacteria. Miquel found 750,000 living bacteria in a block of ice 
from Lac de Joux which had been preserved for eleven months. 
Atmospheric microbia resisted thirty-six hours’ exposure to a 
temperature of — ioo° C., and revived in three days. 
Higher Education in China , — Perhaps the most efficient 
obstacle of all, not only to mining, but to every other form of 
the economic application of science, lies in the essentially 
anti-scientific character of Chinese education. Official employ- 
ment is the sole and the universal ambition of the Chinese 
people, and the only avenue to it is through competitive literary 
examinations. This is no sham, the examinations being so 
severe that only a minority of the candidates pass, the plucked 
ones coming up year after year, even to old age. The subjects 
of examination are handwriting and style. The former is so 
much prized by the Chinese, that busy men practise it all their 
