OF ARTS AND SCIENCES. 347 



Weight, in grammes, of crucible and felt, after ignition . . 20.2020 



after second ignition 20.2020 



after passing 100 cm^ of strong HCl through the filter 



ten times, washing and igniting ........ 20.2020 



after jiassing 100 cm^ of strong HNO3 through the fil- 

 ter teyi times, washing and igniting 20.2021 



after passing 100 cm* of strong H^SO^ through the fil- 

 ter jive times, washing and igniting 20.2022 



after passing 100 cm* of a mixture of strong HgSO^ 

 and water in equal parts, ten times through the filter, 



washing and igniting 20.2024 



after passing 100 cm* of water, containing in solution 

 50 grammes of NaOH ten times through the filter, 

 washing and igniting 20.2028 



Weight of crucible 20.1932 



„ „ felt 0088 



The whole process, involving, in all, the filtration of five litres of 

 liquid (of which one litre was viscous), more than forty changes of 

 the receiver, together with the ignition, cooling, and weighing of the 

 crucible and felt seven times, was completed in two hours and ten min- 

 utes. The disc of felt was eleven millimetres in diameter. 



