Manchester Memoirs, Vol. xlviii. (1904), No. %%. 



XXII. The collection of Apparatus used by Dalton, 

 now in the possession of the Manchester Literary 

 and Philosophical Society. 



By Francis Jones, M.Sc, F.R.S.E. 



Since the celebration of the announcement of the 

 Atomic Theory in 1893, additional interest has been 

 taken in the collection of apparatus which belonged to 

 Dalton, now in the possession of the Society, and 

 requests for photographs of it have from time to time 

 been received. To meet this wish the Council resolved 

 on March 15th that photographs of the apparatus should 

 be taken for reproduction in the Memoirs, and I was 

 requested to carry out the necessary arrangements. These 

 have now been completed, and the most interesting 

 portions of the apparatus are represented on the following 

 nine plates. Before describing these, it may be of interest 

 to note how the apparatus came into the possession of the 

 Society. Dr. Dalton died in 1844, and by a codicil to his 

 will bequeathed "all his chemical and other philosophical 

 instruments and apparatus " to his friend and pupil, Dr. 

 William Charles Henry, by whom they were presented to 

 the Society. They were placed in a glass case near the 

 door of the meeting room, and some of them were 

 exhibited at the Loan Collection of Scientific Apparatus, 

 held at South Kensington in 1876. Professor Roscoe 

 contributed a note on this exhibit which appeared in the 

 Proceedings for 1876, page JJ. Subsequently, in 1890, 

 the most interesting pieces of apparatus were placed in 

 new cases in the Library and carefully arranged by 

 Professor Dixon in the positions they now occupy. To 

 both Sir Henry Roscoe and Professor Dixon I am indebted 

 for some of the descriptions of the apparatus which follow. 



July is/, igo4. 



