Mr. Daniell on the Barometer. 81 



vour, from memory and such rough notes as I have preserved, to 

 recompose the paper, with a full conviction that the facts narrated 

 are of sufficient importance to call for immediate publication, and 

 satisfied, by the opinion of those who are well qualified to judge, 

 that there is sufficient proof of their existence to satisfy all im- 

 partial minds that the subject is well worthy of that further inves- 

 tigation which it was my purpose to propose to the Royal Society. 

 A new law has now been promulgated by the President of the 

 Society, and every thing henceforward published in the Philoso* 

 pkical Transactions must be considered as proved. The council 

 will doubtless immediately drop the notice which has always 

 hitherto been published in the preface to the volumes, that " they 

 do not pretend to answer for the certainty of the facts or pro- 

 priety of the reasonings contained in the several papers published* 

 which must still rest upon the credit or judgment of their respec- 

 tive authors ;" and they will, of course, be careful that this law 

 is administered with impartiality. In such a regulation I, as an 

 humble individual, cannot but acquiesce ; but, with many others 

 I imagine, I shall always be found to resist the curtailment of the 

 hitherto-acknowledged right of an author to withdraw a paper» 

 any time previous to the decision of the council upon its publica- 

 tion. 



In the year 1823 I presented to the Royal Society a paper upon 

 the Construction of the Barometer, the substance of which I af- 

 terwards published in my volume of Essays, the original paper 

 having been committed to the archives of that learned body. I 

 therein stated my reasons for differing from the high authority of 

 the President, upon the cause of the existence of elastic matter in 

 barometer tubes, suggested by him in a paper upon " the electrical 

 phenomena exhibited in vacuo," and published in the Philosophi- 

 cal Transactions for the year 1822. Sign. Bellani also arrived at 

 the same conclusion as myself, from a series of experiments which 

 he undertook, expressly to determine whether the air or vapour, 

 the last portions of which are found to remain so obstinately in 

 barometers and thermometers, is introduced with the mercury, or 

 is a portion of that which originally occupied the tube before the 



Vol. XX. G 



