48 
NATURE 
[Way 18, 1871 

The first law of motion laid down by Sir Isaac Newton 
(Princip. Math. Jes. Ed. tom. i. p. 15) is not a universal law, 
but is only capable of a restricted application. The incapacity of 
matter to alter its condition, whether of rest or motion, is a 
doctrine which becomes untenable when we examine matters 
which are always proprio motu altering their condition. Grave as 
such a statement may at first sight appear, we must begin with it 
if we wish to arrive at the truth. 
Motion is the property which matter possesses of always changing 
its position relatively to other matter, and each little atom of the 64 
elementary substances known tochemists contains a certain amount 
of tendency to move ; this is a part of its nature, it would not be 
what it is without this; as that great mathematician, M. Poisson, 
says, the tendency to move resides init. The five gaseous ele- 
ments, for instance, have each their respective amounts of ten- 
dency to move residing in the atoms of which they are composed. 
Prof. Faraday says, in his “ Researches in Chemistry,” p. 454, “a 
particle of oxygen is ever a particle of oxygen—nothing can in 
the least wear it. If it enter into combination and disappear 
as oxygen—if it pass through a thousand combinations, animal, 
vegetable, and mineral—if it lie hid fora thousand years, and 
then be evolved, it is oxygen with its first qualities—neither 
more nor less. It has all its original force, and only that; the 
amount of force, which it disengaged when hiding itself, has again 
to be employed in a reverse direction when it is set at liberty.” 
Now what is the meaning of the word force which Prof. Faraday 
uses here ? is it not the certain amount of tendency to move which 
I mentioned before? 
A particle of oxygen contains a certain amount of tendency to 
move, without which it would not be a particle of oxygen at all ; 
and this tendency it can never get rid of, ‘it has all its original 
force, and only that.” 
What, then, does the Conservation of Force doctrine amount to 
in plain English ? 
It amounts to the simple admission that the tendency to move 
is a property of matter inseparable from it and coexistent with it, 
and it is this tendency to move which is the cause of all the 
changes which we observe around us. 
There is, however, nothing new under the sun, for the old 
doctrine of Argan in Ze Aalade Jmaginaire is revived again ; 
when Argan answers his examiner for a licence to practise in 
medicine, he says :— 
Mihi a docto Doctore 
Domandatur causam et rationem quare 
Opium facit dormire 
A quoi respondeo 
Quia est in eo 
Virtus dormitiva 
Cujus est natura 
Sensus assoupire. 
Many a clever student has laughed at this answer who little 
thought that research and experience would confirm it so strongly 
as they now do. 
The virtues of opium are chiefly dependent on the morphia 
which it contains, and morphia is one of the vegetable alkalis 
containing nitrogen in combination with carbon, oxygen, and 
hydrogen. The wrtes dormitiva of morphia is the certain amount 
of tendency to move inherent in this combination ; and this ten- 
dency, if the morphia is exhibited in the human subject, comes in 
contact with and retards the tendencies to move which certain 
component parts of the body possess, and produces that state 
which we call sleep. The salts of morphia are largely used to 
allay pain and producesleep. Dr. Bence Jones says in his Croonian 
Lectures on Matter and Force, p. 84, ‘‘ Stimulants, tonics, and 
evacuants may perhaps not only take part directly in the motions 
of any part of the body, but they may also promote or retard 
the conversion of one motion into other motions. Specifics and 
alteratives may directly as well as indirectly change the motions 
in the system. And sedatives and narcotics may have the same 
double action in retarding or stopping the motions that take place. 
This view will almost lead us to consider all medicines as altera- 
tives, and if so we may perhaps place stimulant and sedative 
medicines at the two extremes of the alterative actions; the 
stimulants giving rise to the greatest increase of motion, and the 
sedatives allowing the least motion or the nearest approach to 
rest.” 
The practical student of our day, when he speaks of terrestrial 
matter being at rest, means that it is then moving at the same 
rate of motion as the earth itself. Prof. Ansted treats of motion 

thus :—‘‘The first and greatest lesson that the students of 
Geography and Geology must learn is that motion is not limited 
to masses of bodies, but is actually taking place always and 
under all circumstances within all masses, whether solid, liquid, 
or gaseous, and often without approaching the surface.” —“ Physi- 
cal Geography,” p. 2. 
The Universe is one mighty system of changes, and these 
changes arise from the inseparable connection between matter 
aud motion ; and Dr. Bence Jones says truly, ‘‘ The question 
between materialism and spiritualism is in fact only a question 
between ponderable and imponderable materialism.” 
Trinity College, Oxford N. A. NICHOLSON 

THE BIG GUN OF WOOLWICH 
Ae Se considered as a weapon of terrible 
power or simply as a specimen of skilful and suc- 
cessful forging, the 35-ton Fraser cannon is without 
parallel, Of extraordinary strength and proportions, 
and withal so carefully, and one might almost say, ele- 
gantly finished, this magnificent gun is indeed a master- 
piece well worthy of the greatest factory in England, from 
which it emanates. Cannon of larger dimensions have, 
it is true, been produced, capable actually of delivering a 
heavier projectile than that employed with the Woolwich 
weapon, but none of them are to be in any way compared 
with this, either in respect to battering power or length of 
gange. That the gun is, moreover, not merely a show 
production, as was the case with the monster Krupp cannon, 
but a really serviceable and efficient fire-arm, is shown by 
its endurance of the severe test to which it was subjected 
at proof. On this occasion the 7oolb. projectile was thrown 
from the gun by the enormous charge of 13olbs. of gun- 
powder—the largest, in fact, that has ever been safely 
consumed in any fire-arm—the explosion being without 
the slightest injurious effect upon the steel bore or sur- 
rounding wrought-iron castings. The solid cylinder of 
iron which constituted the shot issued forth at the terrible 
velocity of 1,370 feet per second, and, after travelling some 
fifty yards, buried itself in the butt of loose earth to a 
depth of thirty-three feet. 
The pressure of the gas at the time of explosion was, 
as may be supposed, exceedingly great, and herein 
obviously lies the great difficulty to be overcome in the 
construction of large guns; this pressure or strain, we 
find, increases in a much greater ratio than the amount of 
powder that is burnt would appear at first sight to justify, 
and for this reason large guns require to be proportion- 
ately much strongerthan littleones, Thus, in the present 
instance, when a charge of but 75lb. of powder was fired, 
the pressure of the gas upon the copper piston at the rear 
of the projectile was shown to be seventeen tons per 
square inch, while 13olbs. of powder (not double the former 
charge therefore) gave a pressure amounting to sixty-four 
tons on the square inch, It has, by the way, been ques- 
tioned whether this method of estimating the pressure, 
by means, namely, of a copper piston which is pushed in 
upon itself, affords a strictly reliable test, but in any case 
there can be no doubt that the strain upon the gun is in- 
creased in a greatly increasing ratio to the quantity of 
powder consumed. When we state, therefore, that the 
weapon withstood in every part this excessive strain, and 
that, under ordinary circumstances, the cartridge will 
contain but golbs. of powder, there is every reason to 
believe in the solidity and perfection of the structure. 
The data obtained by the firing of the gun at proof 
lead us to hope for very successful results from its employ- 
ment. It is calculated that at a distance of fifty yards the 
heavy projectile would be thundered forth with such force 
as to penetrate fourteen and a half inches of solid iron, 
an armour plate such as no vessels of our present con- 
struction are enabled to carry. At two thousand yards— 
at upwards of a mile, therefore—the shot would possess 

