1892.] 



Presents. 



439 



it yet does much, harm when closed, by bringing down the impure air, 

 which, if undisturbed, would have a less injurious effect. 



It is to be regretted that this investigation does not promise to 

 yield much of practical value ; nevertheless, as we cultivate not only 

 fruits but flowers, so, for the same reason that we cultivate the latter, 

 it is thought that these experiments will repay the attention of 

 physicists. The colours produced by such simple materials as a little 

 dust and a little vapour are as beautiful as anything seen in nature, 

 and well repay the trouble of reproducing them. 



Presents, April 28, 1892. 



Transactions. 



Baltimore : — Johns Hopkins University. Circulars. Yol. XI. 

 No. 96. 4to. Baltimore 1892. The University. 



Medical and Chirurgical Faculty of the State of Maryland. 

 Transactions. Session 93. 8vo. Baltimore 1891. 



The Faculty. 



Berlin : — Gesellschaft for Erdkunde. Verhandlungen. Bd. XIX. 



Nos. 2-3. 8vo. Berlin 1892. The Society. 



Physikalische Gesellschaft. Yerhandlungen. Jahrg. X. 8vo. 



Berlin 1892. The Society. 



Bucharest : — Societate de Sciinte Fizice. Buletinul. Anul 1. 



Nos. 3-4. 8vo. Bucuresci 1892. The Society. 



Calcutta : — Indian Museum. Indian Museum Notes. Yol. II. 



Nos. 1-5. 8vo. Calcutta 1891. The Trustees. 



Cambridge, Mass. : — Museum of Comparative Zoology. Bulletin. 



Yol. XXIII. No. 1. 8vo. Cambridge 1892. The Museum. 

 Cracow: — Academie des Sciences. Bulletin International. Mars, 



1892. 8vo. Cracovie. The Academy. 



Frankfort-on-Oder : — Naturwissenschaftlicher Yerein. Helios. 



Jahrg. IX. Nos. 7-10. 8vo. Frankfurt a.O. 1891. 



The Society. 



Genoa : — Societa Ligustica di Scienze Naturali e Geografiche. Atti. 



Yol. III. No. 1. 8vo. Genova 1892. The Society. 



Leipsic : — Konigl. Sachs. Gesellschaft der Wissenschaften. Abhand- 



lungen (Math.-Phys. Classe). Bd. XYIII. No. 3-4. 8vo. 



Leipzig 1892. The Society. 



Liege : — Societe Royale des Sciences. Memoires. Ser. 2. Tome 



XVII. 8vo. Bruxelles 1892. The Society. 



Liverpool : — Free Public Library. Catalogue of the Reference 



Department. Part 3. 4to. Liverpool 1892. The Library. 

 London : — Institute of Brewing. Transactions. Vol. V. No. 5. 



8vo. London 1892. ~ The Institute. 



