Chemistry and Phystes. 75 
ture of the electric arc is very imperfect ; and they believe that 
any reasoning based upon the absence of nitrogen is imperfect, for 
it cannot be shown conclusivly that nitrogen has really been absent 
in the experiments hitherto conducted. ey contend against the 
hypothesis that if cyanogen bands are present in the solar 
spectrum they are due to vapors of carbon uncombined in the 
upper cooler region of the chromosphere. It appears to them 
that nitrogen may be recognized in the solar atmosphere through 
cyanogen when free nitrogeu might not be detected.— Proc. R. 8., 
XXX, pp. 152,494. Nature, Oct. 28, 1880. pa 
10. On the behavior of gases under the influence of electrical 
discharges.—Professor E. WirprMANN in a paper not yet con- 
cluded, describes his method of experimenting and gives some pre- 
liminary results. He arrives at a confirmation of fact previously 
stated by him: that a gas may be rendered luminous by electric 
discharges without any corresponding elevation of temperature.— 
Ann. der Physik und Chemie, No. 6, 1880. ps 
ll. A theoretical and practical treatise on the manufacture 
of Sulphuric acid and Alkali; by Grora Lunex. Vol. II 
London: 1880.— 
caustic soda. Every operation, as well as the plant for carrying 
it out, is described with minuteness and illustrated by drawings 
to scale, 
This volume will excite less interest than the first in as much 
as the manufacture of sulphuric acid is very general, while that of 
alkali is in this country conducted by but few firms and by these 
n a very limited scale; yet a study of the technical and com- 
mercial bearing of this great industry is therefore the more nec- 
essary, in order to determine whether its exclusion from the list 
of American enterprises is due to remediable or irremediable 
In Europe only at certain favored centers, where sulphur, 
