1813.] ihe Hon. Henry Cavendish, 13 



theories ; has shown that each of them is capable of explaining 

 the phenomena of chemistry in a satisfactory manner ; that it is 

 impossible to demonstrate the truth of either ; and he has given 

 the reasons which induced him to prefer the phlogistic theory 

 to the other, which the French chemists were unable to refute, 

 and which they were wise enough not to notice. Nothing can 

 be a more striking proof of the influence of fashion even in 

 science, and of the unwarrantable precipitation with which 

 opinions are rejected or embraced by philosophers, than the 

 total inattention paid by the chemical world to this admirable 

 dissertation. Had Mr. Kirwan adopted the opinions of Mr. 

 Cavendish, when he undertook the defence of phlogiston, 

 instead of trusting to the vague experiments of inaccurate 

 chemists, he would never have been obliged to yield to his 

 French antagonists, and the antiphlogistic theory would never 

 have gained ground. 



Such were the chemical papers published by Mr. Cavendish. 

 They contain five notable discoveries : all of them brought nearly 

 to perfection by that illustrious author. These are: 1. The 

 nature and properties of hydrogen gas. 2. The solvent of lime 

 in water when the lime is deposited by boiling. 3. The exact 

 proportion of the constituents of atmospherical air, and the fact 

 that these constituents never sensibly vary. 4. The composition 

 of water. 5. The composition of nitric acid. It is proper to 

 add, that Mr. Cavendish was the first person who showed that 

 potash has a stronger affinity for acids than soda. His experi- 

 ments on the subject are to be found in a paper on mineral 

 waters published in the Philosophical Transactions by Dr. Donald 

 Monro. 



11. Electrical Papers, 



The papers published by Mr. Cavendish on electricity are only 

 two ; but they constitute, perhaps, the most elaborate of all his 

 investigations. His first paper is entitled, An Attempt to 

 explain some of the Principal Phenomena of Electricity hy 

 Means of an Elastic Fluid, (Phil. Trans. 177I3 vol. Ixi. p. 

 5S4.) This paper is very long ; and contains a very complete 

 mathematical theory of electricity, deduced from the hypothesis 

 that there exists an electric fluid, the particles of which repel 

 each other, but are attracted by all other matter with a force 

 inversely as some less power of the distance than the cube. 

 This paper is not susceptible of abridgment ; but it deserves the 

 careful study of every electrician. iEpinus, about the same 

 time, adopted the same hypothesis, and published a book on the 

 same subject, replete with valuable information ; but he does not 

 carry the subject quite so far as Mr. Cavendish. Besides the 

 value of this* paper ia a philosophical point of view, it claims 



