TRANSACTIONS OP THE SECTIONS. 39 



Prof. Grove communicated a notice by M. Gassiot, of a repetition of his experiment 

 on the production of electricity without contact. 



On a Method of Electrotype, hy which the Deposilion on Minute Objects is 

 easily accomplished. By L. L. B. Ibbetson, F.G.S. 



From the difficulties which arose from the application of plumbago, in the ordinary 

 manner, a portion of the plumbago was united with a solution of phosphorus in naph- 

 tha, and the article to be electrotyped immersed in it. It thus became covered with a 

 coating, on which the metal was deposited in a beautiful and uniform manner. Some 

 specimens of cactuses thus covered with metal were exhibited. 



On the Alternate Spheres of Attraction and Repulsion, noticed hy Newton, 

 Boscovich and others ; and on Chemical Affinity. By Thomas Exley, A.M. 



These phsenomena have not been explained by means of fixed general principles, 

 but may be explained by the two principles of a new theory, which are these : — 



1st. That every atom of matter consists of an indefinitely great sphere of force, 

 varying inversely as the square of the distance from the centre : in a very small concen- 

 tric sphere the direction is from the centre, and is called repulsion ; at all other dis- 

 tances it acts towards the centre, and is called attraction. 



2nd. Atoms are of different sorts when their absolute forces, or their spheres of re- 

 pulsion, are unequal. 



These simple principles, duly carried out and rightly applied, are sufficient to ex- 

 plain all the phsenomena of the universe, a proper number of sorts and quantity of 

 each sort being admitted. 



From phaenomena it appears that there are four distinct classes of atoms. Class 1st 

 are denominated tenacious atoms, because they adhere with great force or tena- 

 city: there are fifty-six sorts of tenacious atoms, as oxygen, hydrogen, carbon, &c. 

 Class 2nd embraces the electric atoms, having a much less force, but gi-eater sphere of 

 repulsion than tenacious atoms ; of these there seems to be but one sort. Class 3rd 

 are aethereal atoms, constituting tethereal fluids ; of these there appear to be several 

 sorts ; their absolute forces are very much less than even those of electric atoms, and 

 their spheres of repulsion much greater. Class 4th, not concerned in this paper, com- 

 prises atoms which have an exceedingly small absolute force, and also an exceedingly 

 small sphere of repulsion ; its atoms may be called microgenal atoms. 



Newton, Boscovich and others, conclude from observation, that near the centres of 

 atoms there are several alternations of attraction and repulsion ; Dr. Priestley says 

 that the phaenomena of nature cannot be explained without them; hence the true theory 

 of physics ought to show that such alternations exist. The author proceeds to prove 

 that they result from his principles. 



In the earth's atmosphere we recognize very distinctly the tenacious, the electric, 

 and the aethereal atoms; the tenacious atoms extend to about the altitude of forty-five 

 miles, as is known by the refraction and reflexion of light ; the electric atoms must 

 extend much higher, and the aethereal class to a very great altitude, perhaps some 

 hundreds of miles. The upper parts pressing on the lower give a considerable density 

 to the three classes near the earth's surface. The space occupied by a given portion of 

 tenacious atoms is diminished by pressure, and increased by an elevated temperature, 

 that is, by an accession of aethereal matter. 



which it was proved that a different galvanic result is produced upon the nerves of au 

 animal at a certain period after death, if the current acts upon the nerve of motion, or 

 centrifugal nerve only, from that which ensues if the mixed nerve, centrifugal and cen- 

 tripetal, be subjected to the current ; in the former case the muscular contraction takes 

 place at the interruption of the direct current, or that which passes from the nervous 

 centre to the extremities, and the commencement of the inverse current, or that which 

 passes in the opposite direction ; while in the latter case the reverse effect obtains, the 

 contraction taking place at the commencement of the direct and at the interruption of 

 the inverse current. 



