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 the greatest mo- 

 ment to public safety that 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 practical impor- 

 tance. In the Smithsonian Eeport for 1877 the Institution published 

 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 especially 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 Jeffries, 

 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 occupied 

 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 parties 

 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 applicant 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- 



* Tho following memoirs on this interesting topic have been published by Professor 

 Jeffries : 1. " Dangers from Color-Blindness in Railroad Employes and Pilots," Jan- 

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

 "Incurability of Congenital Color-Blindness," a memoir read at a meeting of the Suf- 

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

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

 and its practical relations. (Delivered Ai^ril 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,vaJ Institute at Annapolis, Md., 

 March 3, 1880.) 



