The Progress of Chemical Industry. 
645 
with electricity as an illuminant, while, in many cases, it has been 
superseded by mineral oils, which are now so abundant and cheap, 
and of which the “ flashing point ” may be said to be almost a burn- 
ing question. If, however, gas is losing ground as an illuminant, it 
seems to be gaining it as a source of power, and there are prospects 
of a considerable increase in the use for this purpose of hydrogen 
and its compounds, containing far less carbon than ordinary 
coal-gas. 
In metallurgy also, in addition to the improvements in the 
manufacture of steel already mentioned, many noteworthy dis- 
coveries have been made. One of the most important of these is 
perhaps that of the production of aluminium on a cheap scale, and 
in quantities sufficient for various applications to ordinary use. It 
seems somewhat remarkable that the progress in the use of a metal 
at once so light and so strong is not more rapid. The applications 
of some of the more modern alloys, such as phosphor-bronze, seem 
also susceptible of considerable further development. The extensive 
manufacture of sodium affords another instance of what was formerly 
the mere subject of a laboratory experiment being now conducted 
upon a commercial scale. 
It is in the domain of organic chemistry, which has been defined 
to be the chemistry of the hydro-carbons and their derivatives, that, 
as I hjave already observed, the most wonderful development has 
taken place within the last half-century. Who, for instance, in 
1840 could have foreseen the important part that aniline was to 
play in dyeing and colouring? It was not, I think, till 1856 that 
Perkin’s mauve was really brought into commercial use, but since 
that time what a rainbow of colours has been produced from coal- 
tar — from what would have seemed a most unpromising source ! 
How brilliant are their hues, but as yet, in many cases, alas, how 
fugitive ! It is a source of some satisfaction to know that the woad, 
the native cruciferous plant with which our ancient British pre- 
decessors stained their bodies, is still cultivated among us for the 
purpose of dyeing wools, even though it has acquired the name 
of Isatis tinctoria and the colouring extract is now classed as an 
indigotin. 
Among inorganic colours I may here briefly mention ultramarine, 
which, instead of being patiently produced by the careful treatment 
of lapis lazuli and sold at many shillings an ounce, is now manu- 
factured by the ton and quoted by the hundredweight. Would that 
the artificial colour was as fine and permanent as the natural ! I 
have, in my own time, seen it supersede smalts as a colouring matter 
in paper-making, and I have known its use not unfrequently accom- 
panied by the abundant presence of sulphuretted hydrogen as a pro- 
duct of its decomposition. 
Not only colouring matters but our flavours and scents have 
been synthesised, though art, if superseding nature for a time, must 
eventually acknowledge her inferiority, even in pear-drops. What- 
ever our aesthetic feelings under these circumstances may be, we 
cannot but admire the skill and scientific energy by which such 
VOL. IV. T. S. — 15 U U 
