15 



13- Exhibits from the laboratorv of Columbia Univer- 

 sity by Professor C. E. Pellew and Dr. S. A. Tucker. 



a. Calico Printing. The production of insoluble azo col- 

 ors in the cotton fibre. 



b. Viscose. Exhibition of Process and Samples of the 

 new form of Soluble and Amorphous Cellulose known 

 as Viscose. 



c. Electrochemistry. The Persulphates and Percarbonates 

 of Alkaline Metals, Prepared by Electrolysis of the 

 Normal Salts. 



14. Exhibits from the Laboratory of the College of 

 THE City of New York. 



a. Three different types of ray filters to contain either 

 liquids or gases and suitable for photographic or purely 

 chemical work. Exhibited by Dr. L. H. Friedburg. 



b. Red sublimate of Nitro-diphenylamin and Yellow crys- 

 tals of quinone-oxim. Exhibited by Dr. L. H. Fried- 

 burg. 



E 



ELECTRICITY. 



Ix Charge of Geo. F. Sever. 



Exhibit of new Apparatus by Qiieen & Co. through Mr. 

 O. T. Louis. 



a. Horizontal Mag^net D'Arsonval GalYanometer. 



b. A new Automatic Self-Focusing Arc Lamp. 



c. Acme Testing Set. 



d. A complete 1 2" X-Ray Outfit with Self- Regulating Tube. 



e. A new Lantern Galvanometer. 



f, A new Portable Photometer. 



g. A new Portable Cable Testing Galvanometer. 



