108 Professors Liveing and Dewar, On volatile gases, etc. 
hydrogen, shewed a ray which seemed to be identical in position 
with the brighter green nebular ray; so that it is probable that 
the nebular stuff may yet be found in the earth’s atmosphere. 
The evidence of the existence in the earth’s atmosphere of 
the gas, or gases, which produce the spectrum of the solar corona 
is stronger, for not only do the spectra of the most volatile 
atmospheric gases include a ray which fits, within the limits of 
probable error of observation, the place of the chief green coronal 
ray, but several other rays which correspond with strong rays 
which have been observed in the corona. 
No ray, however, has been traced in these spectra, correspond- 
ing to the green auroral ray, which is perhaps due to the less 
volatile gas krypton. On the other hand one of the strongest 
rays, emitted mainly at the negative pole, at \ 3587, is at about the 
place of a strong auroral ray, and the authors suggest that the 
electric discharges to which the aurora is due may be of a nature 
similar to that which makes the glow about the negative pole in 
an exhausted tube. 
The spectra suggest the presence of more than one unknown 
substance in the most volatile portion of the atmosphere, but 
further observations are needed to unravel their complexity. 
— 
On a method of comparing affinity-values of acids. By 
H. J. H. Fenton, M.A., and H. O. Jones, B.A., Clare College. 
\Read 18 February 1901.] 
When the hydrazone of oxalacetic acid is heated with pure 
water it yields the hydrazone of pyruvic acid with evolution of 
carbon dioxide, but in presence of dilute acids of sufficient concen- 
tration a totally different change occurs; in this case no gas is 
evolved and pyrazolon-carboxylic acid results. 
I. 
II. 
CH 2 COOH 
I 
C : N 2 HPh 
I 
COOH 
CH 2 COOH 
C : N.N 
COOH 
\Ph 
ch 3 
I 
= CN 2 HPh + C0 2 
I 
COOH 
CH 2 . CO 
I i 
= C : N . NPh + H 2 0 
I 
COOH 
