LECTURE VI.] HISTORY OF CHEMISTRY. $7 



Generally speaking, it is increased by supplying more heat, and 

 this explains why certain combinations only take place at a 

 high temperature. 4 



During the combination of two elements, the atoms 

 arrange themselves with their opposite poles towards each 

 other, and mutually discharge their free electricities, whereby 

 the phenomena of heat and of light are produced. The old 

 doctrine is explained at the same time Corpora non agunt nisi 

 soluta (substances do not interact unless dissolved), since free 

 motion of the smallest particles is only possible in the liquid 

 state. When a substance is subjected to the action of the 

 electric current, the latter restores to the atoms their original 

 polarity, whereby the substance breaks up into its constituents. 



A compound of the first order is not electrically (nor yet 

 chemically) inactive, since, during the combination, only one 

 pole of each atom is neutralised ; it is still unipolar, and it can 

 enter into further combinations (of the second order) which are 

 likewise endowed with electrical forces ; but the intensities of 

 these forces diminish, the higher the order of the compound 

 becomes, since the stronger poles are, in general, neutralised 

 first. According to Berzelius, the specific unipolarity of the 

 oxides depends solely upon the radical or element combined 

 with the oxygen. The latter gives rise to the most powerfully 

 electro-positive and electro-negative substances (alkalies and 

 acids) ; and as it cannot, therefore, be itself the cause in both 

 cases, it cannot be the cause in either. 5 



All chemical reactions, and, consequently, the phenomena 

 of heat and light that accompany them, are, according to 

 Berzelius, produced by electricity, which " thus seems to be the 

 first cause of the activity all around us in nature." 6 



If a substance C is to decompose the compound AB^ so 

 that B may become free, then C must be able to neutralise a 

 greater amount of the electrical polarity of A than B can. 

 Further, a mutual exchange between AB and CD only occurs 



4 Lehrbuch. Second Edition, Vol. 3, Dresden (1827), part I, 73-74. 

 5 Ibid. 76. 6 Ibid. 77. 



