THE CORROSION OF CONDENSER TUBES. 
cupric chloride solution is very distinctly attacked despite the small 
current passing from the solution to the brass. It is considered that 
an electric current slows down, but does not necessarily inhibit corro- 
sion of a cathode. By raising the current density sufficiently it is 
possible that all corrosion, even in a cupric chloride solution, may_ be 
prevented. Experiments have shown, however, that a current as large 
as 20 to 25 amperes per 1,000 square feet is insufficient to prevent a 
70 : 80 brass tube from being rapidly corroded by such a dilute solution 
of cupric chloride as a one-twenty-fifth normal solution. Some sug- 
gestions are made whereby the usefulness of the electrolytic protection 
process may be extended by special manipulation of it in the early part 
of the life of a tube, with the object of forming a thin continuous layer 
of calciuri carbonate over the surface of the tube. 
"4 
Sh : Bw \ # 
\ ay iN \ 
cian 
359 
