Notices respecting New Books. 379 



gen, according as the compound contains to every atom of sul- 

 phur one, or two, or three atoms of oxygen. 



" Now, according to Mr, Dalton, Sulphureous acid actually 

 contains 13 parts by weight of sulphur to l4 of oxygen, and 

 therefore its atom consists of one atom of sulphur to two atoms 

 of oxygen ; and Sulphuric acid consists of 13 parts by weight of 

 sulphur to 2 1 of oxygen, or one atom of the former to three 

 atoms of the latter. 



" This hypothesis therefore is perfectly consistent in the above 

 examples. 



" The comparative lue'ght of each atom being thus ascertain- 

 ed, the relative diameter of the atom is foimd by comparing its 

 relative weight with the specific gravity of the substance of which 

 the atom is an integi-ant particle. But as this part of Mr. Dal- 

 ton's svstem is not essential to our present purpose, we shall not 

 pursue it. 



" Not only do elementary atoms unite in definite proportions, 

 but also compound particles unite in the same manner. Thus 

 both sulphuric acid and potash are compouiul particles, being 

 each oxyds, the one of sulphur and the other of potassium. But 

 as potash combines with two different proportions of sulphuric 

 acid, one being just double the quantity of the other, the com- 

 pound, sulphnt of potash, may with propriety be considered as 

 composed of an atom of potash with an atom of sulphuric acid, 

 and the compound, snper-sulphat of potash, may be considered 

 as consisting of one atom of potash to two atoms of sulphuric 

 acid. 



" Mr. Dalton gives the term Binary atom to any compound 

 of two elements in which one atom of each is combined, and 

 hence there can be but one species of binary compound of any 

 two elements. 



" A Ternary ^tom is composed of two atoms of one of the 

 elements with one atom of the other, and hence there may be 

 two species of ternary atoms of the same element, according as 

 one or other is in the greater proportion. Thus an atom of ni- 

 trous oxyd is a ternary compound of two atoms of azote and one 

 atom of oxygen ; and on the other hand, nitrous acid is also a 

 ternary compound of the same elements, but consisting of one 

 atom of azote with two atoms of o.wgen. 



"A Quaternary yllom is composed of three atoms of one 

 element with one atom of the other, and hence also there may 

 be two species of quaternary atoms as either element predomi- 

 nates ; aiTd so on of the other nuuibers. 



" We shall now proceed to mention a number of facts that 

 illustrate in a striking manner the chemical union of substances 

 in dejinite proportions, 



" If 



