The Microscopk. 279 



mounts in this or in an}- other country. His work is perfect, 

 and the microscopist so fortunate as to possess any of his slides 

 is to be congratulated. In the treatment of the blood of various 

 animals his methods seem to be especially successful. The re- 

 sults are at least all that can be desired. 



NCV/S • FRO/A 

 THE WORKERS 



Iridescent glass. — A visitor at the Metropolitan Museum of 

 Art in New York cannot fail to notice in his tour of the galleries 

 the exquisite ancient Cyprian glass ware, with its gorgeous 

 iridescence surpassing in brilliancy of color anything ever pro- 

 duced b}'^ artificial means. So far as is at present known, this 

 effect can be produced only by the corrosive action of the air 

 and moisture of the soil in which these objects have been buried 

 for centuries. 



Glass having a similar appearance, but without the same bril- 

 lianc}' of color, has been found elsewhere, and a certain degree 

 of iridescence has been imparted to glass of modern manufac- 

 ture by flashing it during the annealing process with stannous 

 chloride, thus depositing on the glass an exceedingly thin film, 

 which decomposes the light and thus yields a pleasing color 

 effect. Glassware of this kind is beautiful, and was at one time 

 much in demand, but at present it can hardly be found on sale. 



Through the courtesy of General L. P. Di Cesnola, director of 

 the Metropolitan Museum of Art, the writer has been enabled to 

 examine specimens of ancient Cyprian glass secured by him in 

 his archseological explorations in Cyprus. 



A microscopical examination of this glass shows that the sur- 

 face is covered with exceedingly thin transparent films formed 

 by matter dissolved from the glass. The body of the glass is 

 pitted over its entire surface with minute cavities, which are 

 circular or elliptical or oblong in outline, and either spherical, 

 ellipsoidal, or cylindrical in respect to their concavity, and the 

 films conform to the pitted surface of the glass. These films, of 



