ANALYSIS IN COMMUNICATION RESEARCH 



499 



of heavy metal impurities in such metals as aluminum or nickel, or in 

 examining waters after use in corrosion experiments. 



In order to reduce the errors of weighing in microgravimetric 

 analysis, it is ob\'iously desirable to obtain transformation products 

 having the greatest possible mass. To facilitate manipulation, it is 

 also desirable to deal only with products of a coarse crystalline nature 



Fig. 6 — The glass hot stage assembly shown here provides for the determination of 

 melting points or the sublimation of volatile substances under the microscope. 



