Manchester Memoirs, Vol. xlviii. (1904), No. %%. 5 



Plate VII. 



1. A differential thermometer. 



2. Balance used by Dalton, made by Accum. 



3. A wet and dry bulb hygrometer, made by H. H. Watson, 



of Bolton. 



Plate VIII. 



I and 2. Phials containing platinum and amalgam of tin and 

 mercury. 



3. A glass alembic. 



4. A Florence flask, with cork and valve for determining the 



specific gravity of gases. 



5. A spark eudiometer of thick glass, with copper wires fitted to 



the neck. 



6 and 7. Two Phials, one containing an amalgam of bismuth 

 and mercury. 



8 — ig. Phials, containing respectively iodine, cochineal, 



mercury, gunpowder, mercury, grana sylvestra cochineal, 

 quercitron bark, resin, mercury, madder, lead and mercury 

 and creosote. 



Plate IX. 



1. 4 and 6. Portions of Pepy's apparatus for the analysis of 



gases. I is the eudiometer, with elastic ball attached. 

 For analysis of air, a solution of nitric oxide in ferrous 

 sulphate is used to absorb the oxygen. See paper by 

 W. H. Pepys in the Philosophical Transactions for 1807, 

 page 247. 



2. A glass pipette. 



3. An earthenware cup used as a mercury bath, 



5. Wooden blocks used by Dalton to explain his atomic theory. 

 7. A glass bottle with brass cap. 



