268 
Notes. 
[March, 
as may be judged from the fadt that, after being shut up in a box 
for five days, it was still visible in total darkness. Prof. Morton 
expresses the opinion that further advances in this direction may 
develop discoveries of most surprising character. 
We gather from the same journal that Mathey, a Neufchatel 
chemist, communicates the following fadts relating to the same 
subjedt. The phosphorescent dials, he states, are usually made 
of paper or thin card-board, enamelled and covered with an ad- 
hesive varnish, upon which is dusted, with a fine sieve, powdered 
sulphide of barium. The sulphides of strontium and calcium 
possess the same property ; but our authority affirms they lose 
their phosphorescence more quickly than the barium salt. When 
the dial has lost its self-luminous qualities they may be restored 
by an hour’s exposure to sunlight, or by burning near it a few 
inches of magnesium wire. 
In a paper presented to the Academy of Sciences, on the 
“ Classification of Colours and the Means of Re-producing 
Coloured Appearances by Three Special Photographic Proofs,” 
M. C. Gros distinguishes two categories comprised under the 
word “ colours ” — lights and pigments. The elementary lighis 
which by their mixture produce all kinds of shades are the green, 
violet, and orange rays. The elementary pigments which by 
their mixture produce all kinds of shades are red, yellow, and 
blue. To obtain diredtly the elementary tints of rays and of 
pigments it is sufficient to look through a prism at a white stripe 
upon a black ground, and at a black stripe upon a white ground. 
In the first case an orange, green, and violet spedtrum is seen ; 
and in the latter case a blue, red, and yellow spedtrum. In the 
former case the orange, green, and violet are elementary rays ; 
and in the latter the red, blue, and yellow are rays combined two 
and two. The author describes an apparatus which he names 
the chromometer, and by means of which he produces the photo- 
graphic effedt above mentioned. 
A daily paper, speaking of the prizes at the Paris Lottery, uses 
“ carbide of natrium ” as a synonym for carbonate of soda. 
Another newspaper paragraph describes the death of a man who 
fell into a cistern of “ caustic and potash.” 
According to the “ Revue Britannique ” ether is consumed as 
an intoxicant by ladies of rank in England, the grass in Hyde 
Park being strewed with empty bottles flung from carriage 
windows. 
According to M. Galippe, human hair cut during life has a 
special odour which remains after the adtion of potassa or of 
any other reagent. Hairs which fall off naturally are inodorous, 
dull, not silky to the touch, and present a special phenomenon of 
alternating colouration. The hairs of the Chinese, even after 
the adtion of potassa, possess an odour of musk, which is inten- 
sified at higher temperatures ; their sedtion is not round or oval, 
