COMMITTEES ON BEHALF OF THE GOVERNMENT 233 
that the permanent marks should take the form of cast-iron 
blocks coated with zinc. It was suggested to the Secretary of 
War, however, that these blocks might be injured or destroyed as 
a result of galvanic action between the two metals. He, there- 
fore, requested through the Acting Quartermaster-General that 
a committee of the Academy be appointed to advise him as to 
the probability of such action in the metal headstones. 
The letter was as follows: * 
“ QUARTERMASTER GENERAL’S OFFICE, 
“ Washington, D. C., January 8, 1867. 
“Sir: It having been suggested to the War Department that the coating with 
zinc of the iron head-blocks, with which it is proposed to mark soldiers’ graves, 
will produce galvanic action that will tend to a destruction of the iron blocks, the 
Secretary of War has directed me to submit the subject to the Academy of 
Sciences here, with a view to obtain an intelligent opinion on it, and to ascertain 
if there be any good ground for the apprehension. 
“In obedience to this direction, I respectfully submit the subject to you with a 
request that you will present it to the Academy of Sciences and advise me of their 
opinion thereon, that I may make report thereof to the Secretary of War. 
“T am, very respectfully, your obedient servant, 
“D. H. RuckKEr, 
“ Acting Quartermaster General, Brevet Major General. 
“The PRESIDENT OF THE ACADEMY OF SCIENCES, Washington, D. C.” 
A committee consisting of Joseph Henry, J. H. C. Coffin and 
Joseph Saxton was appointed by the President on the same day. 
It reported on January 17, as follows: 
“ NATIONAL ACADEMY OF SCIENCES, 
“ Washington, January 17, 1867. 
“Sir: In compliance with your request, the undersigned, a committee of the 
National Academy, appointed to examine the proposed cast-iron head-blocks for 
soldiers’ graves, and state whether, in their opinion, the coating of zinc will tend 
to produce a galvanic action destructive to the iron, respectfully report as follows: 
“The head-block submitted to the committee is a hollow truncated pyramid 
of cast iron, on one side of which, in raised figures, is the No. 12,646, and on 
the top, also in raised letters, the name of a soldier, his regiment, and a date, 
probably that of his death. This block is entirely covered inside and out with 
* Rep. Nat. Acad. Sci. for 1866, p. 17. Sen. Misc. Doc. no. 44, goth Congress, 1st Session. 
