FOR THE ADVANCEMENT OF SCIENCE. 125 



1. When ethereal matter is contained in a vessel under pressure, a tena- 

 cious atom placed in it will acquire an atmospherule of ethereal matter, the 

 stronger sorts will occupy the lower strata, and, if electric atoms be present, 

 they will form the lowest stratum. When two tenacious atoms are present, 

 they will condense ethereal matter in the line between them, and especially 

 the stronger sorts, and the electric atoms will be brought into that line. 



2. The mutual actions of the whole mass in the vessel is a repelling force 

 between any two atoms varying inversely as their distance. 



3. If the absolute force, or spheres of repulsion, of the tenacious atoms in 

 the vessel be increased or diminished, the repelling force mentioned in pro- 

 position 2 is not altered. Here it was shewn that equal volumes of gases 

 contain an equal number of atoms. 



4. That the densities of gases vary as the compressing force. 



5. That the volume varies as the temperature. 



6. That the absolute force of a tenacious atom being given, there is a cer- 

 tain magnitude of its sphere of repulsion, at which it will retain a maximum 

 quantity of electric atoms. 



7. Elements combine chemically in definite proportions. 



Many of the above propositions were stated as known facts, but 

 here they were shewn to be necessary consequences from the two 

 principles of the theory. 



8. Taking each elementary atom as representative of a volume ; then, in 

 all strictly chemical combinations, that is, whenever there is any condensa- 

 tion, the resulting volume is always, without exception, either one or two 

 volumes exactly, whatever may be* the number of volumes which combine. 



This law, it was observed, contains and extends the theory of 

 volumes. After proving it from the theory, it was proved by in- 

 duction, from fifty-seven compounds, all as far as known to him, 

 whose specific gravities had been determined by experiment ; and 

 the calculated specific gravities in every case, except boro-choloric 

 acid, agreed with those by experiment within the allowable errors 

 in such cases. It was observed that these facts could not be ex- 

 plained on any of the received theories. The thanks of the section 

 were voted to Mr. Exley by acclamation for this paper. Dr. Dalton 

 expressed his approbation of this doctrine of volumes, and now saw 

 reasons for their uniting which he had not before discovered. Mr. 

 W. Herapath and Dr. Thompson (of Glasgow) spoke highly in praise 

 of the theory, which they considered one of the greatest boons ever 

 bestowed upon chemistry. 



A paper on the power of certain gases, carbonic oxide, and de- 

 fiant gas, to prevent the union of oxygen and hydrogen, by Dr. 

 Henry, was next read. This qucestio vexaia has perplexed the best 

 chemists ; and the author, after many experiments, concludes that 

 the interference is only exercised by gases having an affinity to oxy- 

 gen. 



Mr. Herapath next read a paper on Arsenical Poisons, which he 

 illustrated, by relating the circumstances of a memorable trial which 

 recently took place at Bristol, and attracted great public attention, 

 as one hardly equalled in the annals of criminal jurisprudence. — 

 We regret our limits prevent our giving an abstract of this inter- 

 esting Paper. 



