548 Progress in Science * [October, 
might be enunciated in a precise and definite form, were very different from 
the simple expressions which apply to the ideal condition. The new laws 
became in their turn inapplicable when from the gaseous state proper we 
passed to those intermediate conditions which, it had been shown, linked with 
unbroken continuity the gaseous and liquid states. As we approached the 
liquid state, or even when we reached it, the problem became more compli- 
cated ; but its solution even in these cases might confidently be expected to 
yield to the powerful means of investigation we now possess. 
Among the more important researches made of late in physical chemistry, 
those of F. Weber on the specific heat of carbon and the allied elements, of 
Berthelot on thermo-chemistry, of Bunsen on speCtrum analysis, of Wiillner 
on the band- and line-spectra of the gases, and of Guthrie on the cryohydrates 
were mentioned. 
Cosmical chemistry abounded in fads of the highest interest. Hydrogen, 
which, if the absolute zero of the physicist did not bar the way, we might 
hope yet to see in the metallic form, appeared to be everywhere present in the 
universe. It existed in enormous quantity in the solar atmosphere, and it had 
been discovered in the atmospheres of the fixed stars. It was present, and 
was the only known element of whose presence we are certain, in those vast 
sheets of ignited gas of which the nebulae proper are composed. Nitrogen 
was also widely diffused among the stellar bodies, and carbon had been dis- 
covered in more than one of the comets. On the other hand, a prominent 
line in the speCtrum of the Aurora Borealis had not been identified with that 
of any known element ; and the question might be asked — Does a new element, 
in a highly rarefied state, exist in the upper regions of our atmosphere ? Or 
o 
are we with Angstrom to attribute this line to a fluorescent or phosphorescent 
light produced by the electrical discharge to which the aurora is due ? This 
question awaited further observations before it could be definitely settled, as 
did also that of the source of the remarkable green line which is everywhere 
conspicuous in the solar corona. 
Here Dr. Andrews paid a tribute to the memory of Angstrom, whose great 
work on the solar spedtrum will always remain as one of the finest monuments 
of the science of our period. The influence, he said, which the labours of 
o 
Angstrom and of Kirchhoff had exerted on the most interesting portion of 
later physics could scarcely be exaggerated ; and it might be truly said that 
there were few men whose loss would be longer felt or more deeply deplored 
than that of the illustrious astronomer of Upsala. 
Passing to the application of science to the useful purposes of life, Dr. 
Andrews referred to the application by Neilson of the hot-blast to the smelting 
of iron. The Bessemer steel process and the regenerative furnace of Siemens 
were later applications of high scientific principles to the same industry. But 
there was ample work yet to be done. The fuel consumed in the manufacture 
of iron, as, indeed, in every furnace where coal was used, was greatly in 
excess of what theory indicated ; and the clouds of smoke which darkened the 
atmosphere of our manufacturing towns, and even of whole districts of 
country, were a clear indication of the waste, but only of a small portion of 
the waste, arising from imperfeCt combustion. The depressing effeCt of this 
atmosphere upon the working population could scarcely be overrated. At some 
future day the efforts of science to isolate, by a cheap and available process, 
the oxygen of the air for industrial purposes might be rewarded with success. 
The effeCt of such a discovery would be to reduce the consumption of fuel to 
a fractional part of its present amount ; and although the carbonic acid would 
remain, the smoke and carbonic oxide would disappear. But an abundant 
supply of pure oxygen was not now within our reach ; and in the meantime 
he would suggest that in many localities the waste products of the furnace 
might be carried off to a distance from the busy human hive by a few hori- 
zontal flues of large dimensions, terminating in lofty chimneys on a hillside 
or distant plain. A system of this kind had long been employed at the 
mercurial mines of Idria, and in other smelting-works where noxious vapours 
were disengaged. With a little care in the arrangements, the smoke would 
