SOME USES OF THE LOW POTENTIAL ALTERNATING 
CURRENT IN A CHEMICAL LABORATORY. 
MILO S. WALKER, PH. D. 
Teacher of Chemistry and Physics, Racine High School. 
In this paper the author does not claim to have discovered 
any action of the arc light that is not already known to chem- 
ists. .'4 
He desires only to give a few suggestions as to the way in 
which the highest temperature at our command can be obtained 
and used in every chemical laboratory supplied with a fixture 
for incandescent lighting. 
Many colleges and secondary schools are now equipped with 
these fixtures and others can obtain them at but little cost. 
There is no practical reason why we should not use these con¬ 
veniences for some experiments which cannot be performed with 
a Bunsen burner or a blow pipe. 
In some recent experiments with lamps designed for optical 
projection I have had experience in working with some of the 
arc lights now in practical use. It was noticed that the alter¬ 
nating current of about 50 volts and 5 amperes, now generally 
used for incandescent lighting, furnishes an excellent arc for 
chemical experimentation. It is very efficient and can be han¬ 
dled by students as easily and safely as a Bunsen burner or al¬ 
cohol lamp. 
The apparatus required is an iron or wooden stand, a screw 
clamp, like those used for holding burettes, insulated copper 
wire, some electric light carbons and a rheostat. 
The copper wire should consist of a piece of the so-called 10 
ampere flexible lamp cord connected at one end with a plug set 
in the socket from which an electric lamp has been removed. 
The two parts at the other end of the twisted cord are left free. 
