I. RESEARCH. 475 



III. Apparatus for Measuring Gases and for determining the Solubility of 

 Ga&es in Water. 



No. 19 is an apparatus with a graduated tube, probably used by Dalton for 

 the determination of the laws regulating " the absorption of gases by water 

 " and other liquids," read October 21st, 1803. " Manchester Memoirs." 

 2nd Series. Vol. 1. 



No. 20 is a graduated glass tube attached to a bottle of india-rubber, also 

 probably used in his researches on the absorption of gases by water. 



No. 21, No. 22, are divided eudiometer tubes, employed by Dalton for 

 measuring the volumes of gases. 



No. 23 is a spark eudiometer. 



Nos. 24, 25, 26 are glass tubes, pipettes, and funnels graduated by Dr. 

 Dalton and used by him for measuring gases. 



No. 27 is a graduated glass bell-jar, used for measuring gases. 



No. 28 is a phial, with graduated tube attached by cement, for collecting 

 and measuring gases. 



Nos. 29, 30 are stoppered phials, with the bottoms cut off, used as gas jars 

 for collecting and measuring gases. 



No. 31 is a thousand grains specific gravity bottle, with its counterpoise 

 of lead stamped " 175" by Dalton, and paper labelled in his handwriting 

 " bottle balance." 



No. 32 is a pipette. 



No. 33, square bottle of thin glass, fitted with brass caps, and probably used 

 for the determination of the specific gravities of gases. 



No. 34 is an earthenware cup, used by Dalton as a mercury-trough, and 

 containing a small phial with mercury. 



Nos. 35, 36 are bulb tubes, with graduated*scales, serving for the determi- 

 nation of the coeflicients of expansion of gases. 



No. 37 is a Florence flask with cork 'and valve for determining the specific 

 gravity of gases. 



No. 38 is a glass alembic. 



IV. Weights, Balances, Apparatus, Reagents, and Specimens used by Dalton. 



No. 39, eleven phials, containing creosote, iodine, amalgam of bismuth and 

 mercury, quercitron bark, grana sylvestra, cochineal, and other substances, 

 labelled in Dal ton's handwriting. 



No. 40, three divided blocks, used by Dalton for the illustration of his lec- 

 tures ; these are not, however, the balls an inch in diameter (referred to in his 

 latest memoir on the " Analysis of Sugar ") which he employed occasionally 

 in his lectures, as illustrating his newly-discovered laws of combination and 

 the atomic theory ; these appear, unfortunately, to be no longer in existence. 



No. 41 is a common pair of scales used by Dalton. 



No. 42, a pair of apothecary's scales and weights employed by Dalton, with 

 a paper of weights made of wire, labelled in his handwriting, " 100th grains." 



No. 43 is a box of weights used by Dalton, and containing a pill box 

 labelled " Platina," another pill box labelled "Hund," and containing 100th 

 of grains, and another wooden box containing brass gramme weights, labelled 

 " Weights, French ;" the other ordinary weights are of lead. 



No. 44 is Dalton's pocket balance, consisting of a small pair of apothecaries' 

 scales, with beam about 4 inches long, and having the pans attached by 

 common string ; it is contained in a tin case for the pocket. 



No. 45 is a penholder used by Dalton. 



No. 46, leaden grain weights made by Dalton from sheet lead, and stamped 

 in numbers by him. 



No. 47, iron punches used by Dalton for this purpose. 



