REPORT OF THE SECRETARY. 21 



coasts, on railroads, at draw-bridges, and elsewhere, are usually cliaracter- 

 ized by special colors, it obviously becomes a matter of tlie greatest mo- 

 ment to public safety tliat those immediately in charge of such signals, 

 or appointed to observe them, should be known to be entirely free from 

 any imperfection or disqualification in this direction. The subject has 

 accordingly with justice assumed a character of great x)ractical impor- 

 tance. In the Smithsonian E-eport for 1877 the Institution T)ublished 

 the translation of a paper by Prof. F. Holmgren, of Stockholm, in which 

 the vital consequence of this subject in many of the vocations of life, 

 and especiallj^ those connected with traveling and communication by 

 sea and by land, were strongly pointed out; and to this memoir is un- 

 doubtedly due in large degree the present appreciation of the subject. 

 An edition of this work had been contemplated by Prof. B. Jay Jeflries, 

 of Boston, who has himself conducted a very extended series of independ- 

 ent researches in the same direction.* 



LABORATORY WORK. 



A large part of the time of the chemist of the Institution is occuiiied 

 in determining the character of minerals sent to the Institution, with the 

 request for information. Under a rule of the Institution, of which a copy 

 is herewith submitted, the examination of minerals for private x>arties 

 and private interests is confined to a simple qualitative examination, or, in 

 other words, an indication of the more important elements contained 

 therein. It is a comparatively easy matter to ascertain whether a cer- 

 tain specimen contains gold, silver, lead, or other metal, and examina- 

 tions of this kind are made daily. In all cases, however, where an act- 

 ual chemical analysis or assay is required, it is only done at the request 

 or in behalf of some branch of the government, or for some other i)ublic 

 purpose ; in all other cases the ai)plicant is referred to professional chem- 

 ists for the investigation. It will, of course, be readily understood that 

 if the Institution once establishes the precedent of making such assays 

 and analyses, it would soon require the services of dozens of chemists, 

 thus involving expense for which no adequate provision could be made, 

 and interfering with the business of those who depend upon such work 

 for a subsistence. 



In the report of the chemist, which is submitted in the Appendix, will 

 be found a statement of the general character of the chemical work con- 

 ducted during the year, among which have been quite a number of in- 



* The follov/iog memoirs on this interesting topic have been published by Professor 

 Jeffries : 1. " Dangers from Color-Blinduess in Railroad Emi)loy6s and Pilots," Jan- 

 uary, 1878, Boston. (From tha Ninth Annual Reiiort of the State Board of Health. ) 2. 

 "IncurabiUty of Congenital Color-Blinduess," a memoir read at a meeting of the Suf- 

 folk District Medical Society, February 23, 1878. (Printed in the Boston Medical and 

 Surgical Journal IMarch 28, 1878. ) 3. " Color-Blindness." A lecture ou color-blindness 

 and its practical relations. (Delivered April 11, 1878, before the Society of Arts, at 

 the Institute of Technology, Boston.) 4. Paper " On Color-Blindness and its Dangers 

 on the Sea." (Read before the United States Na,val Institute at Annapolis, Md., 

 March 3, 1880.) 



