TRANSACTIONS OF THE SECTIONS. 73 



which arc similar to each other (which demand two atoms), and an equator giving a 

 plane at right angles to the poles (which demand three at least), he obtains a group 

 of five as the nucleus of the first molecular species to be looked for in the laboratory — 

 the nucleus, for the volume of the molecule is supposed to be determined by an elec- 

 tric and calorific atmosphere, which invests the constituent atoms to a great extent, 

 and which tends ever to be of a spheroidal form, whatever the form of the nucleus. 



Now it appears a priori, that is, when viewing this first molecular body of five ele- 

 mentary atoms purely in reference to its own structure and to the medium of light in 

 which it is conceived to exist, that it must possess the following properties: — 1st. In 

 the fully insulated or individualized state, that is, the aeriform, it must be the lightest 

 of all gases ; for it follows from a law which the author communicated to the Physical 

 Section, that equal volumes of different gases are to be expected to contain equal num- 

 bers of molecules, or numbers in a simple ratio to each other. 2ndly. It must be pre- 

 eminently elastic ; for where there is no loss of heat, we can only suppose a defect in 

 elasticity in a gas to be caused by what we know to cause such defect in other cases, 

 viz. violence done by the compression or strain of the elastic structure. Now of this 

 molecule the structure is the simplest and most stable possible. More than any others, 

 therefore, it is secure from strain, and it may therefore be expected to be eminently 

 elastic under the greatest pressures. 3rdly. It must in relation to its quantity of matter 

 be the most highly refractive and reflective of all molecules; for it is well known and 

 is demonstrated by all aeriforms, that it is between similars that the most intense re- 

 pulsion takes place. Now this molecule is more similar to the medium of light than 

 any other, its every element consisting of a single particle. Between it and light there 

 will therefore be a maximum repulsion, that is, a maximum reflexion or refraction, as 

 the case may be. 4thly. If, therefore, it be viewed as in the solid state, this molecule 

 would be of a metallic nature, and it may be expected to perform the functions of a 

 metal. Now these are the well-known properties of the first of the laboratory gases so 

 well known by the name of hydrogen. But there is this difference between these pro- 

 perties as obtained experimentally and as deduced from the author's theory. In the 

 former case they are obtained only as so many individual facts with regard to hydro- 

 gen, which are empirically or incidentally coexistent in the same body. In the latter 

 they are seen to coexist rationally, to imply each other, and in fact to be expressions, 

 in different points of view, of one and the same structure. 



Assuming this simplest of insulable molecules to represent hydrogen, its atomic 

 number and weight is of course 5, from which there results, happily for the author's 

 theory, a remarkable coincidence between the current atomic weights on the hydro- 

 gen scale and those which this theory gives, not as conventional like the other, but 

 representative of absolute structure. Thus the tendency in the present day, as it was 

 long ago, is to regard the weight of hydrogen as one-sixteenth of that of oxygen, one- 

 twelfth of that of carbon, &c, and therefore representable by -5 instead of 1*0, as has 

 been usual. Hence the current tables become adapted to that which this theory re- 

 quires, simply by moving the decimal point one degree to the right. The equivalent 

 of H being -5, that of O from 8"0 becomes 80, that of C from 6-0 becomes GO, and so 

 on; care being taken, however, to distinguish well between equivalents and atomic 

 weights, since the equivalent of active elements, whose place is usually on the poles of 

 a central body, consists of tico atoms at least, else symmetry of structure in a single 

 equivalent of the compound is impossible. 



It is chiefly in reference to the chemical functions of molecules, however, that this 

 theory shows its value and its power. This was shown in reference to hydrogen in 

 its relations to carbon, of which latter the genesis and model were next exhibited; 

 and which proved to be a five-sided obtuse bipyramid composed of 30 particles of 

 light, as hydrogen is a three-sided acute bipyramid ; both viewed in reference to 

 tangent planes. Thus the model of an atom of carbon shows seven regions for the 

 attachment of other bodies, one on each pole, and five on the equator. Charge it fully 

 with atoms of the simplest possible hydrocarbon, viz. CH, and we obtain C-|-C 7 H 7 = 

 C 8 H 7 . Now on inspecting works of experimental chemistry, this is seen to be the 

 formula of caoutchouc, the most highly charged hydrocarbon which tropical vegeta- 

 tion alone supplies. 



In this molecule the nucleus is an atom of carbon; but nature delights in inver- 

 sion ; as by inverting the vegetable she gives the animal kingdom. Let us take an 



