VI. FLUORESCENT BODIES. 231 



92 la. Drawing of the Apparatus used in 1842 by Prof. 

 Daniel Colladon to show the total refraction of light in the interior 

 of a vein of water. See Comptes Rendus, vol. 15, p. 800. 



Prof. Daniel Colladon, Geneva. 



This remarkable experiment was made on a large scale by the French 

 Government on several occasions at public festivals. 



92 lb. Apparatus for determining the Refractive Index 

 of Solids and Liquids. 



C. CzechovicZj Teacher of Physics at the Gymnasium, 

 Be lost ok, Russia. 



Consists of a horizontal board and vertical divided pillar with movable 

 support for a telescope. The body under examination is put on a glass plane 

 attached over a slit in the board, through which a light beam is reflected by 

 an inclined mirror. A linear mark made on the upper surface of the glass 

 (if the body is solid), or on the upper surface of the vessel (if the body is 

 liquid), is brought in coincidence with a movable wire which touches the 

 upper plane of the body. The distance of this wire and the height and incli- 

 nation of the telescope give the necessary data for calculating the index with 

 sufficient approximation. 



VI. FLUORESCENT BODIES. ' 



922. Fluids showing the Phenomenon of Fluorescence. 



Charles Homer. 



A. Soda salt of anthracene in water. 



B. Fluore seine in water. 



C. Eosine in water. 



923. Fluids showing the Phenomenon of Fluorescence. 



Charles Horner. 



Small Tubes in Stand. 



D. Turmeric in castor oil. 



E. Harmaline in water. 



F. Magdala red in alcohol. 



G. Ebony wood (Amerimuum ebenus) in castor oil. 

 H. Induline in chloroform. 



I. Esculine in water. 



K. Camwood (JBaphia nitida) in castor oil. 



L. Esculetine in water with alkali. 



M. Fraxine (Fraxinus excelsior) in water. 



N. Fustic (Madura tinctoria) in solution of alum. 



924. Selection of eight fluorescent liquids. 



Dr. Th. Schuchardt, Gorlitz. 



Eosine. Extract of Cuba- wood. 



Magdala Red. Aesculine. 



Saffranine. Bichloranthracine. 



Fraxine. Bisulphurous acid. 





