374 On Dalton’s Theory of Chemical Composition. (Nov. 
5th. In sulphuret of iron, each atom of iron united to one atom 
of sulphur. ~ 
Gth. In magnetic pyrites, each atom of iron united to two atoms 
of sulphur. ; 
7th. In pyrites of Soria, each atom of iron united to three atoms 
of sulphur. : 
8th. In common pyrites, each atom of iron united to four atoms 
of sulphur. 
9th. In sulphate of iron, each atom of red oxide of iron united to 
two atoms of sulphuric acid. 
In the ninth compound we have aneexample of the union of two 
compound atoms; and in the same manner various other compound 
atoms are found to be united in compounds which contain more 
than two elements. 
Indeed any atom at present supposed to be simple may afterwards 
be found to be compounded of others more simple; for upon this 
principle it is not concluded that an atom of any known element is 
in its smallest possil/e state of division. The word atom is intended 
to express merely the smallest division which is found of any 
element without decomposition. * 
Thus an atom of carbonic acid, one of the elementary particles 
constituting that elastic fluid, is only capable of division into oxygen 
and charcoal. It is possible that atoms of oxygen and charcoal may 
be further divided, but we do not yet know that the division is prac- 
ticable. Neither is it understood that the relative weights of the 
atoms of the five elements, the combinations of which we have been 
comparing, are precisely as 1, 5°6, 7, 14, and 50. It is obvious that 
their relative weights can, upon Mr. Dalton’s principle, be deter- 
mined only by the agreement of a great number of nice, and often 
slifficult, analyses; and in proportion as more accurate analyses are 
* It is not assumed that the ultimate elementary particles or atoms of matter are 
absolutely indivisible. But in support of the opinion that they have remained un- 
divided since the creation of the world, and that the permanence of the specific 
properties of all material objects depends upon their atoms remaining undivided, 
Mr. Dalton has referred to the following observations of Sir Isaac Newton :— 
«* It seems probable to me that God in the beginning formed matter in solid, 
massy, hard, impenetrable, moveable, particles, of such sizes and figures, and with 
such other properties, and in such proportion to space as most conduced to the end 
for which he formed them; and that these primitive particles being solids, are in- 
comparably harder than any porous bodies compounded of them; even so very 
hard, as never to wear or break in pieces, no ordinary power being able to divide 
what God himself made ove in the first creation. While the particles continue 
entire, they may compose bodies of one and the same nature and texture in all 
ages; but should they wear away, or break in pieces, the natare of things de- 
pending on them would be changed. Water and earth, composed of old worn 
particles and fragments of particles, would not be of the same nature and texture 
now with water and earth composed of entire particles in the beginning, And 
therefore that nature may be lasting, the changes of corporeal things are to be 
placed only in the various separations and new associations, and motions of these 
permanent particles; compounded bodies being apt to break, not in the midst of 
solid particles, but where those particles are laid together, and trusts only in a few 
points,” —Horsley’s Newton, iv. 260. 
; 
| 
| 
