564 SEC. 13. CHEMISTRY. 



2538. Glass Chemical Vessels (retort, bottle, and flask or 

 receiver) used in the chemical laboratory of the University of 

 Edinburgh during the latter half of last century. Exhibited to 

 show the contrast between them and vessels used for similar 

 purposes at the present day. 



Edinburgh Museum of Science and Art. 



2396. Apparatus employed by John Dalton in his Re- 

 searches. 



The Council of the Literary and Philosophical Society oj 

 Manchester. 



The apparatus employed by John Dalton in his classical researches, 

 whether physical or chemical, was of the simplest and even of the rudest 

 character. Most of it was made with his own hands, ^and that which is 

 exhibited has been chosen as illustrating this fact, and as indicating the genius 

 which with so insignificant and incomplete an experimental equipment was 

 able to produce such great results. The Society has in its possession a large 

 quantity of apparatus used by Dalton, most of which however consists of 

 electrical apparatus, models of mechanical powers, models of steam engines, 

 air pumps, a Gregorian telescope, and other apparatus of a similar kind, which 

 was either bought or presented to him. It has not been thought necessary to 

 exhibit these, but rather to show the home-made apparatus with which Dalton 

 obtained his most remarkable results. 



I. Meteorological and Physical Apparatus made and used by Dr. Dalton. 



Throughout his life Dalton devoted much time and attention to the study 

 of meteorology ; indeed his first work, published in 1793, was entitled " Me- 

 " teorological Observations and Essays," and his last paper, printed in 1842,* 

 (Mem. Lit. and Phil. Soc. VI. 617) consists of auroral observations. Hence 

 the first of Dalton's apparatus which claim attention are the meteorological 

 instruments. 



No. 1 is Dalton's mountain barometer, with accompanying thermometer, 

 made for him by the late Mr. Lawrence Buchan of Manchester. The baro- 

 meter is enclosed in a wooden case, which Dalton was accustomed to cany in 

 his hand. 



Several home-made barometers used by Dalton in his observations are in 

 possession of the Society. They are all of them filled, and the scales pre- 

 pared, by Dalton himself, and are simple siphon tubes with a bulb blown on 

 at the bottom to serve as a mercury reservoir. These are attached to plain 

 pieces of deal, upon the upper part of which the paper scale is pasted. One of 

 these, which has probably also served for tension experiments (No. 2), has 

 been placed in the collection. 



Many of the thermometers appear also to have been home-made. 



No. 3 is a mercurial thermometer* evidently made and graduated by Dr. 

 Dalton, and marked with his initials, J. D. The freezing point of this ther- 

 mometer was tested recently by Mr. Baxendell, who found that it had not 

 altered since the instrument was graduated. 



Another (No. 4) is of the same kind, and bears the date 1823. 



* Vide Life of Dalton by Dr. Henry, published by the Cavendish Society ; Memoir of 

 Dr. Dalton and the History of the Atomic Theory, published in the Memoirs of the 

 Literary and Philosophical Society of Manchester, 2nd Series, Vol. I. ;. Dr. Lonsclale's 

 Life of Dalton, Longmans, 1874. 



