'testing foe color-blindness. 
February 17, 1880, it was “ordered by the Secretary of the Treasury 
of the United States that all persons applying for either a renewal of 
license or an original license, as pilots on steam vessels, shall be 
required to undergo a visual examination, in order that it may be 
determined whether such person can properly distinguish the colored 
lights used as signals on steam vessels ; and, in future, inspectors will 
issue pilots’ licenses only upon certificates of surgeons of the United 
States Marine-Hospital Service that applicants therefor fulfill all the 
requirements of the rule referred to.” 
March 9, 1880, this order was “so modified as to allow pilots em- 
ployed at places remote from a Marine-Hospital station to be examined 
by any respectable resident physician, whose certificate that such pilot 
is exempt from the disease known as color-blindness shall accompany 
the license and oath of office of such officer when sent to any board 
of local inspectors for renewal of his license in the manner provided. 
Upon the receipt of the certificate a license shall be issued the same as 
though said examination had been made by a Marine-Hospital surgeon. 
This modification is not to be applied to applicants for original licen- 
ses ; they, in all cases, must be examined in the manner provided,” 
i. e., by Marine-Hospital surgeons. 
The standard manual adopted by the United States Government 
and provided for the medical officers of the Army, Navy and Marine- 
Hospital service is “ Color-Blindness : its Dangers and Detection,” by 
Dr. 13. Joy Jeffries. 
The method of examination adopted, is the one fully described in 
this manual, namely, Prof. Holmgren’s, with certain colored worsteds. 
This is also the test used by medical expei’ts in detecting color-blind- 
ness amongst railroad employes, and the one used in the schools, and 
in the recent investigations of the color-sense of uncivilized tribes in 
various parts of the world, a mutual language not being necessary for 
examiner and examined. 
The value of the test depends upon its being carried out strictly in 
accordance with Prof. Holmgren’s directions, given in this manual. 
For this purpose it is absolutely necessary to have the correct colors 
and shades of worsteds, which are not easily procured, therefore 
At the Meeting of the American Ophthalmological Society at Newport, July 25, 
1879, it was resolved, 
“ That Dr. B. Joy Jeffries be requested to make such arrangements as he may 
find practicable to enable the members of the Society and others to procure 
suitable collections of colored worsteds for testing for color-blindness.” 
In compliance with this request the following arrangement has been 
made with the undersigned. They agree on the receipt of $2.50 to 
send by mail, post-paid, to any address, a complete and accurate set of 
worsteds, including the tests. On the receipt of $4.50 they agree to 
send, post-paid, to any address, a set of the worsteds and the manual 
of Dr. Jeffries above referred to. 
N. D. WHITNEY & CO., 
129 Tremont Street. 
Boston, Mass., U. S. A.