430 Serentific Intelligence. 
quantity of CO present. A one per mod aqueous solution of 
pyrocatechin or of hydroquinone go causes the appearance ni 
once of the methemoglobin bands blood containing oxygen 
while carbonyl blood is dichanwed: In this test, the blood is 
heated with the Jig 0 to 40° for 15 minutes. Be: aa gee 
Ges., rity Sas 
8 
i Sr by the approach or recession of the sources of light, : 
to the left of 6 is a telluric line a=5976°35 iid to the right at's 
a telluric line d=5974'36. When the edge of the solar disc is 
observed it is found that the iron lines change while the telluric 
lines remain in the same position they assume when the center of 
the solar disc is observed.— Comptes Rendus, No. 7, 1880, P. aa 
9. Successive transformations of the photographic sinidigl ih 
prolonged action of light—M. J. Janssen states the followin 
facts in extension of those previously communicated by him: zi 
The ordinary nti Sohne image. (2.) A fir: “ neta state. The 
ond neutral state, opposite to the first, in which the plate 
becomes uniformly éleat under the action of the dev eloper. (5.) 
second negative image, resembling the ordinary negative image, 
but differing from it by intermediate states and by the enormous 
difference of the luminous intensity which is necessary to obta in 
it. (6.) A third neutral state—in which the negative image of the 
second order has co een ae is sy by a dark uniform 
tint.— Comptes Rendus, No. , 9. 
Captain Abney enters in he an venphanation of the reversal of the 
developed photographic image in the Philosophical ay 
ne heteen 1880, p. 200. J. 
hange of the zero point of a thermometer.—Professor ee 
M. Gales shows (1.) that the zero point rises more rapidly in 
vystal = in those made from 
perature; and the effect produced by the elevated temperature 
pei the thermometer more stable under the ach of lower 
temperatures. Professor Crafts shows that the ecard aheing sine: 
back to positions of equilibrium, and probably not to the effects 
of pressure.— Comptes Rendus, Nos. 5 and 7, 1880, pp. rae: 
