266 Dr, Thomson's Answer to the Review of the [April, 



System. Had I allowed three pages to every valuable paper 

 which I had occasion to notice, my System would have extended 

 to 100 instead of 4 volumes. The object which I had in view 

 was to draw a comprehensive and distinct outline, and to leave 

 the student to fill up the minute details by consulting the original 

 papers, to which 1 always refer. I have given, I conceive, all 

 the important additions to our knowledge of flame contained in 

 Davy's paper. Had any thing been omitted, there can be no 

 doubt that our Reviewer would have specified it. Since he has 

 confined himself to general abuse, I may take it for granted that 

 he had no particular omission to point out. 



4. The fourth accusation is so very uncandid that I was sur- 

 prised to meet with it even in this Review, virulent, and hostile, 

 and malignant, as it is. In my short chapter on Electricity, 

 which occupies only 10 pages, I state that in 1803, Berzelius 

 and Hisinger made a capital discovery respecting the action of 

 the galvanic battery in decomposing bodies. They found that 

 oxygen and acids accumulate round the positive pole ; while 

 hydrogen, alkalies, earths, and metals, accumulate round the 

 negative pole. Acids and bases may be made to pass through 

 a considerable column of water, and even to cross each other, 

 in order to accumulate round the poles to which they are respec- 

 tively attracted. In the concluding paragraph I mention that 

 Sir H. Davy took up the subject where Berzehus and Hisinger 

 laid it down. His celebrated dissertation contains merely a veri- 

 fication of the law discovered by Berzelius and Hisinger. I then 

 state his subsequent steps and discoveries. — (vSystem, i. 171.) 



On this statement of mine, the Reviewer descants in four long 

 pages, and affirms in direct terms that the law in question was 

 not discovered by Berzelius and Hisinger, but by Sir H. Davy. 

 To this I answer, that I have quoted the very words of their 

 paper. It was published in 1803 in German and French, and in 

 1806 in Swedish. It was never translated into English; but 

 Davy quotes it in his celebrated lecture, and, therefore, was 

 acquainted with it. My statement being true, I was bound as 

 an honest man to make it ; nor do I see that it takes in the least 

 from the value of Davy's paper. The discovery of Berzelius and 

 Hisinger remained neglected and unproductive, and might have 

 so continued till the present day, had not Davy taken up the sub- 

 ject where they laid it down ; and by his genius and industry, 

 aided by a more fortunate situation, laid it open to all the world; 

 and had he not by his subsequent discoveries awakened the 

 attention of chemists to its great importance as an instrument of 

 analysis. 



The Reviewer mixes these unjust remarks with accusations 

 against me for passing over Davy's electrical discoveries so 

 slightly as I have done. Had he been candid enough to quote 

 the two concluding sentences of my chapter, the true motive of 

 my conduct would have appeared, and his aaimadversioas would 



