— | 
200 LORD RAYLEIGH AND PROFESSOR W. RAMSAY ON ARGON, 
A : A 
Wage S vain 
In the present case a CARDEW voltmeter gave V = 904, V, = 88; and V,” in the 
formula may be neglected. Thus, 
| A 
W= (V + V.)(V — V,.) =A(V — V,) 
= 2°4 X 2°5 = 6:0 approximately. 
The work consumed by the coil when the sparks are passing is, thus, less than 7$5 of 
a horgse-power; but, in designing an apparatus, it must further be remembered that 
in order to maintain the arc, a pretty high voltage is required at the terminals of the 
secondary when ne current is passing in it.—April, 1895. } 
5. Early Experiments on Withdrawal of Nitrogen from Air by means of Red-hot 
Magnesium. 
it having been proved that nitrogen, at a bright red heat, was easily absorbed 
by magnesium, best in the form of turnings, an attempt was successfully made to 
remove that gas from the residue left after eliminating oxygen from air by means of 
red-hot copper. 
Fig. 2. 



















The preliminary experiment was made in the following manner :—A combustion 
tube, A, was filled with magnesium turnings, packed tightly by pushing them in with 
arod. This tube was connected with a second piece of combustion tubing, B, by 
means of thick-walled india-rubber tubing, carefully wired; B contained copper oxide, 
and, in its turn, was connected with the tube CD, one-half of which contained soda- 
lime, previously ignited to expel moisture, while the other half was filled with 
phosphoric anhydride. E is a measuring vessel, and F is a gas-holder containing 
‘atmospheric nitrogen.” 
a 
