266 The Progress of Physical Discovery. [ 



with water, and over which the current of superior air does not disperse 

 itself in the same manner as in the northern hemisphere. 



There are few names more celebrated in chemistry than that of Ber- 

 zelius, Secretary of the Academy of Stockholm, whose work on the 

 Theory of Chemical Proportions, and the Chemical Influence of Elec- 

 tricity, was the first that fixed our ideas on those two fundamental 

 points the relative disposition of the elementary particles of bodies 

 when arrived at a settled combination, and the impulsive force which 

 conducts them to that state, or which obliges them to change it and 

 re-unite themselves in new combinations, either among themselves or 

 with particles of other kinds. The theory of Berzelius supposes the 

 existence of homogeneous substances, formed of atoms or particles of 

 matter, not, indeed, absolutely indivisible, but upon which no mechanical 

 power can effect any further division; and when the chemical forces are 

 equally powerless, the atom is then, as Berzelius calls it, simple. In the 

 inorganic kingdom, the first order of composition results only from the 

 union of atoms of two kinds ; in the organic kingdom, on the contrary, 

 there are always at least three. The atoms composed of the first order 

 unite in their turn into atoms of the second, and those again into atoms 

 of the third and fourth ; but the tendency of atoms to unite diminishes in 

 proportion as their composition augments. For them to act, indeed, 

 beyond a certain degree of composition, circumstances are required over 

 which man has no controul ; and although nature may annually have 

 formed, and perhaps continues to form in the bowels of the earth minerals 

 of a very complicated composition, though chemically homogenous, art 

 is able to produce nothing similar in the rapid operations of chemical 

 laboratories. Berzelius, in tracing the causes which assemble or disperse 

 atoms, has greatly modified the doctrine of Lavoisier, which attributed 

 all combustion to a combination of oxygen with bodies, and the heat pro- 

 duced to the disengagement of the latent caloric which kept the oxygen 

 in a gaseous state before its combination. He showed that other causes 

 of a higher and more general nature were to be looked for, and it is by 

 means of the chemical action of electricity, in the discovery of which he 

 himself had no inconsiderable share, that he recognized these causes. 

 They consist in the electro-chemical affinities of bodies ; oxygen, acids, 

 c. being of the negative character, and hydrogen, alkalis, and salifiable 

 bases, being what are called electro-positive. Thus the combination, or 

 mutual neutralization of chemical agents would be a direct effect of the 

 two kinds of electricity ; and heat and combustion produced by combina- 

 tion would be of the same nature as when caused by lightning or an 

 electric shock, and a stronger affinity would be only a greater intensity 

 of polarization. Berzelius's new Nomenclature, and his new System of 

 Classification of Minerals, which first became known to Europe, by 

 translation, in 1819, may be ranked with his System of Proportions, as 

 some of the most valuable additions to physical science made in our 

 time. 



MM. Gay-Lussac and Welther, in 1811), discovered an acid, formed 

 by the union of sulphur and oxygen, intermediate, between sulphuric 

 and sulphurous acid. It was named hypo-sulphuric, and its salts, hypo-' 

 sulphates. Thenard succeeded in his endeavours to oxygenize water, so 

 far as to saturate it entirely, by making it absorb 616 times its bulk of 

 oxygen gas. Several animal matters, besides metals, possess the power 

 of thus acting upon water, which makes these researches important not 



