J. N. Doekijer.New Method of Spectrum Observation. 307 
with the beantiful effects produced by the passage from the 
lower to the higher heat-level, and shows the important bear- 
ing on solar physics of the results obtained by this new method 
of work 
_ In the flame the two least refrangible of the components of 
6 are seen associated with a line less refrangible, so as to form 
atriplet. A series of flutings and a line in the blue are also 
On passing the spark, all these but the two components of 6} 
are abolished. We get the wide triplet replaced by a narrow 
one of the same form, the two lines of 6 being common to both, 
thus— 
Flame Spectrum | 
End of flutings 
Spark Spectrum 
When the line in the blue disappears on passing the spark, 
two new lines are seen. The spark lines are in the sun, but 
the less refrangible member of the wide triplet and the blue line 
seen in the flame are absent. ; : 
The following are the details of some of the experiments 
which have been made on the above points:— 
Experiment No. 1.—Two pieces of platinum wire were sup- 
ported in a Bunsen flame at a distance from one another of 
about three millimeters. They were then connected with a 
“es machine, in order that the spark might be passed inside 
€ Name. : 
An image of the platinums was then thrown on the slit of 
the Spectroscope by means of a lens. The spectroscope used 
had two dense flint prisms of 60°. 
piece of charcoal soaked in solution of sodium chloride was 
put into the base of the flame first, and then just below the 
Platinum, and the spectrum observed ; it consisted simply of 
the yellow line D. The spark was passed and the spectrum 
again observed ; it now consisted of D plus the lines of hydro- 
gen and some air lines, the red and green Na lines and the 
Steen flutings being still absent 
: ‘periment No. II.—Same arrangements, except that a large 
Induction coil was substituted for the Holtz machine. The 
Same results were obtained with the sodic chloride. 
periment No. [1I.—Metallic sodium was next tried. It 
was found that when the metal was put into the flame just 
