( 607 ) 
§ 5. The construction of the melting apparatus will he readily 
seen from fig. 2. The hard glass tubes always filled with 10 grams 
of the weighed and well mixed complex of the two elements were 
placed in iron cylinders filled with fine sand. Tube and cylinder 
were covered with asbestos; the requisite atmosphere of nitrogen 
was supplied by way of a hard glass gas-inlet-tube. The nitrogen 
was prepared from NH 4 C1 and KNO,, freed from oxygen by means 
of alkaline pyrogallol and sodiumhydrosulphite and dried by sul¬ 
phuric acid. The furnace was constructed of chamotte stone furnished 
regulation of the velocity of cooling. The- iceketlle for the cold 
solderplace of the platinum-platinumrhodium thermoelement (3 mm.) 
is double walled and allows of working for some six hours with 
the single supply of ice; all the conducting wires were isolated by 
glass tubes. 
The galvanometer of Siemens and Halske was verified by deter¬ 
mining the meltingpoints of tin, lead, bismuth, cadmium, zinc, anti¬ 
mony and silver and by making use of the values found by Day 
and Hot.born and by Day and Clement, which were compared with 
the gasthermometer. The reading was taken with the aid of a lens, 
the counting of the time by means of a clockwork, which gave a 
signal every 10 seconds. 
