80 On Recent Progress in the History of 
duction, showing that it has sufficient body and capacity 
for being refined into the best kind of sugar that the market 
could afford. We are convinced that this work of refine- 
ment is merely a matter of time.” 
ON RECENT PROGRESS IN THE HISTORY OF 
PROPOSED SUBSTITUTES FOR GUNPOWDER. 
BY PROFESSOR F. A. ABEL, F.R.S., V.C.P.S., CHEMIST TO THE 
; WAR DEPARTMENT. 
(Delivered at the Royal Institution, May 4th, 1866.) 
HE changes which have been affected in the compo- 
sition of gunpowder since its first application as a pro- 
pelling agent have been limited to small variations in the 
proportions of its constituents. But the modifications 
wihch have from time to time been introduced into the 
details of its manufacture, eg., the preparation of the in- 
gredients, their incorporation, and the conversion of the 
mixture into compact masses (grains, &c.), of different size 
and density, have been sufficiently important and success- 
ful to secure the fulfilment of gunpowder, in a more or less 
efficient manner, of the various requirements of military 
science, and of different branches of industry. 
The characteristics of gunpowder, as an_ explosive 
_material of permanent character, the action of which is sus- 
ceptible of great modification, are mainly subscribable to 
the peculiar properties of the oxidising agent, saltpetre. 
Frequent attempts have been made to replace this con- 
stituent of gunpowder by other nitrates (such as those of 
sodium, lead, and barium) ; but, although materials suitable 
for blasting operations have been thus prepared (such as 
soda-gunpowder, and barytic gunpowder, or poudre saxi- 
Sragine), all mixtures of this class, hitherto produced, have 
exhibited important defects, when compared with gun- 
powder manufactured for propelling purposes. 
The well-known oxidizing agent, chlorate of potash, 
which differs from saltpetre only in containing chlorine in 
the place of nitrogen, is far more energetic in its action 
_upon oxidizable bodies than any of the nitrates. Thus, a 
