ON NEW EXPLOSIVE POWDERS. 
653 
considerable length of time. The fact is that ferric hydrate, even though kept under 
water, decomposes after a time, or more quickly if heated, losing the elements of water, 
and becoming an oxyhydrate, a body insoluble in weak acids and, also unlike ferric hy¬ 
drate, incapable of acting as an antidote to arsenic, that is, incapable of forming ferrous 
arseniate. 
It may be useful again to draw attention to the decided alteration in properties which 
ferric hydrate spontaneously undergoes when exposed beneath the surface of water, or 
when boiled with water, as evidence that this substance (Fe 2 6 HO) is a true analogue 
of hydrate of sodium (Na HO), etc., and not a hydrous ferric oxide (Fe 2 0 3 , 3 H 2 Q). It is 
more reasonable to suppose that in acquiring new properties ferric hydrate becomes 
changed to new compounds than to consider that the changes result from the loss of a 
portion of water already existing as water. Between ferric hydrate (Fe 2 6 HO) and ferric 
oxide'(Fe 2 0 3 ) there would appear to be several oxyhydrates, analyses, etc., of most of 
which have already been given in the ‘ Chemical News ’ (xvii. 56) by Brush and Rodman. 
1. Fe 4 12 HO. 
2. Fe 4 0 10 HO. 
3. Fe 4 0 2 8 HO. 
4. Fe 4 0 3 6 HO. 
5. Fe 4 0 4 4 HO, 
6 . Fe 4 0 5 2 HOi 
7. Fe 4 0 6 . 
In the above formulae, No. 1 represents two molecules of ferric hydrate ; Church found 
a stalactite of true ferric hydrate, native, in Cornwall, and Wittstein gives a similar for¬ 
mula to fresh artificial ferric hydrate. No. 2 is the only oxyhydrate, in this series, still 
unknown, unless, indeed* Haughton’s Kilbride mineral contains this body. No. 3 is 
brown iron-ore from the Hiittenrode Hartz. No. 4 is the formula of a limonite and of 
artificial ferric hydrate altered by age,'—described by Wittstein as having a crystalline 
structure. No. 5 is the mineral gothite, and also the dried oxyhydrate commonly used 
in pharmacy. No. 6 is turgite, hydVo-hematite, or the mineral from Salisbury, Conn., 
analysed by Brush and Rodman. No. 7 represents two molecules of ferric oxide.— 
Chemical News. 
As stated in the March number of the 1 Pharmaceutical Journal,’ M. Jeaunel prepares a 
ferric precipitate, which is soluble, not only in solutions of weak acids or acid-salts, but 
even in water. The substance appears to be a mixture of ferric hydrate, or, when dried, 
oxyhydrate, with a small quantity of ferric oxychloride or oxynitrate. This compound 
merits further investigation. Hitherto peroxide and perhydrate of iron, pure or impure, 
have only been dissolved in water under the extraordinary conditions of dialysis. It 
would be especially interesting to know whether or not M. Jeannel’s compound in the 
dry, or even in the moist, state is an efficient permanent antidote to arsenic.—J. A. 
ON NEW EXPLOSIVE POWDERS. 
BY M. DESIGNOLLE. 
Many improvements having lately been made in the art of war, and particularly in the 
adoption of breech-loading arms, the want has been felt of new powders to meet the re¬ 
quirements of the present artillery. This want has been supplied by M. Designolle, who 
has invented a new system of powders of which carbazotate or picrate of potash is the 
base. These powders are of four kinds, viz. a musket powder, gunpowder for short 
bore cannons, slow gunpowder for cannons with long bores, and an explosive powder for 
torpedoes and projectiles destined for the undermining of fortifications. The principal 
advantages of these new powders are the following:—Increase of balistic power without 
increase of explosive power ; the base remaining the same, possibility of regulating and 
varying the effects between the limits of one to ten ; also of regulating, at will, the ra¬ 
pidity of combustion of this powder, and of increasing the balistic power without chang¬ 
ing the mode of manufacture. Other advantages are—regularity in the manner of ac¬ 
tion ; suppression of sulphur, and consequently of the vapours of sulphide of potassium 
and sulphuretted hydrogen; absence of action on metals and almost entire suppression 
of smoke. Into the explosive powders only two components enter—picrate of potash 
