TRANSACTIONS OF THE SECTIONS. 65 



different Sections are like different countries ; and, leaving the insular seclusion of 

 our special studies, we can pass from one to the other, and gam the advantages of 



foreign travel. . , , ^..i 



From this Chair I must of course regard Chemistry as the centre of the universe, 

 and in speakino- of other Sections I must think of them only in their relation to 

 ourselves. There is tliat rich and ancient country, Section A, which, accordmg_ to 

 the Annual Report, comprises several provinces. Mathematics, Astronomy, Optics, 

 Heat, Electricitv, and Meteorology. 



Mathematics and Astronomy.— It was when the idea of exact weights and mea- 

 sures was projected into it that Alchemy was transmuted into Chemistry. As our 

 science has become more refined in its methods its numerical laws have become 

 more and more significant ; and it may safely be predicted that the more closely it 

 is allied with general physics, the greater will be the mathematical knowledge 

 demanded of its votary. 'But till lately the Chemist and the Astronomer seemed 

 far asunder as the heavens and the earth, and none could have foretold t;hat we 

 should now be analyzing the atmospheres of the sun and stars, or throwing light on 

 the chemical composition of planetary nebulns and the heads of comets. There is 

 in this, too, as in other things, a reciprocal benefit ; for we are encouraged to hope 

 that this celestial chemistry will reveal to us elements which have not yet been 

 detected among the constituents of our globe. , • •• .1 



Lio-ht, Heat, and Electricity.— How intimately are these associated with the 

 cheniical force, or rather how easily are these Protean forces transformed into one 

 another ! The rays of the sun com'ing upon our earth are like a chemist entering 

 his laboratory : they start strange decompositions and combinations not only in the 

 veo-etable kingdom, but also among inorganic gases and salts; they are absorbed 

 selectively by different bodies which they penetrate, or are refracted, dispersed, and 

 polarized according to the chemical composition and structure of the substance. 

 All this has been the subject recently of much scientific research; and I need 

 scarcely remind you of the beautiful art of photography as one of the results of 

 photo-chemistry, or of the benefits that have arisen from a study of circular polar- 

 ization, indices of refraction, and especially spectrum-analysis. In regard to the 

 latter, however, I would remark that while the optical examination of the rays 

 emitted by luminous vapours has yielded most brilliant results, there is another 

 kind of spectrum-analysis- that of the rays absorbed by various terrestrial gases, 

 liquids, and solids— which has already borne valuable fruit, and which, as it is tar 

 more extensively applicable than the other, may perhaps play a still more impor- 

 tant part in the 'Chemistry of the future. The dispersion of the rays of the spec- 

 trum is certainly due to the chemical nature of the body through which they pass; 

 but this is as yet almost unbroken ground waiting for an explorer. As to heat, it 

 has ever been 'the tool of the chemist; and it would be difficult to overestimate 

 the significance of researches into the specific heat or the melting- and boiling- 

 points of elements and their compounds. The laws of chemical combination have 

 been elucidated lately by thermo-chemical researches ; it has been sought to esta- 

 blish a connexion be'tween the absorprion or radiation of heat and the complexity 

 of the chemical constitution of the active body ; while the power of conducting 

 heat, or of expanding under its influence, offers a promising field of inquiry. As 

 to electrical science, one department of it (Galvanism) is strictly chemical ; the 

 electrolytic cell does our work : and indeed we claim half the electric telegraph ; for 

 while the needle may oscillate in Section A, the battery belongs to B. 



Last in Section A comes Meteorology; and there are chemical questions con- 

 cemino- the constitution of the atmosphere, its changes, and the effect of its occa- 

 sional constituents upon vegetable and animal life, which merit the deepest attentioa 

 of the physiologist, pliilanthropist, and statesman. 



If we turn to Section C, there is an outlying province belonging to us— namely, 

 Mineraloo-v, which lies on the frontiers of Geology. A vast and very promising 

 reo-ion is'the orioin and mode of formation of different minerals : this has attracted 

 some explorers during the past year ; but in order to investigate it^properly the 

 a-eolo"ist and the chemist must travel hand in hand. Geology, m demanding ot 

 Ss the analysis of earths and ores, roclcs and precious stones, repays us by bringing 

 to our knowledge many a rare element and strange combination. 



