222 Hmjal Institution. 



are incited to raise our thoughts to the great scheme of 

 the universe, to pass from our transient and temporary ex- 

 istence, to laws which appear eternal in their operation — 

 to recognise one order in the inniiensity of space — and to 

 indulge hopes, that in the future progression of our being, 

 we shall behold fully that magnificent system, which we 

 now see darkly and at a distance. 



Mr. Davy delivered his seventh lecture on Saturday the 

 7th instant. The ideas of the ancients concerning the ele- 

 ments of matter were founded upon superficial observation 

 of the great forms of Nature, and were rather poetical than 

 philosophical. Water, air, earth and fire were supposed to be 

 unalterable: principle, or matter, was considered as consti- 

 tuted by solid, indestructible atoms, as in the school of 

 Epicurus ; or bv regular solids, as among the Pythagorean 

 philosophers. The alchemists considered the rutie results 

 of their operations by (ire, as the principles of things/ 

 salts, oils, phlegm, and sulphurs were the elements which 

 they imaaiued. All these ideas are discarded by modern 

 chemists, who do not pretend to define what bodies are 

 really unchangeable, or the true elements in nature, and 

 speak of compound and simple bodies merely in relation to 

 their own knowledge. The methods by which chemical 

 truths are gained, are analytical or synthetical ; by analysis 

 bodies are resolved into simpler forms of matter ; by syn- 

 thesis they are composed from their constituents; and the 

 test of the accuracy of the process is the correspondence in 

 weight between the compound and its constituents. By 

 the application of weight and measure to chemistry, says 

 Mr. DavV; its results arc rendered certain and uni'hange- 

 able, and independent of any alterations of theory — and it 

 is placed, like astronomy, within the province of the science 

 of numbers and quantity. Mr. Davy divided the sub- 

 stances not yet decompounded, into two great classes- 

 supporters of combustion and inflammable bodies. ]n the 

 first class, he said, there were only two substances as yet 

 known — oxvgen and chlorine. He devoted the remainder 

 of the lecture to the demonstration of the properties of the 

 former. The gas forms one- fifth of the air of the atmo- 

 sphere, and is the principal necessary for combustion and 

 respiration. In its pure form it produces a number of bril- 

 liant results, by acting upon inflammable bodies ; the me- 

 tals burn in it brilliantly and absorb it, and it is a consti- 

 tuent part of most acids and alkalies. Mr. Davy showed 

 a beautiful experiment, in which the same oxygen, by being 

 combined with sulphur, formed an acid, ^nu by being abs- 

 tracted 



