SCIENCE— ADVERTISEMENTS 



:FREAS= 



Freas Electric Laboratory Apparatus 



DEPENDABLE - DURABLE - ECONOMICAL 



Freas Tube Furnace 



A dependable scientific apparatus for making 

 explosive tests of pulverized materials of every 

 -, description. 



' The material to be tested is enclosed in a 



I glass tube, which is then inserted in a metal 



■~*^ tube and securely sealed before placing in 



furnace. The heavy composition hood is a 



protection against injury, in case contents of 



tube should cause explosion. 



This furnace is constructed of the most dur- 

 able materials and itg operation is entirely 

 automatic. 



FREAS TUBE FURNACE ^'""^ ^""^ 'D^cHprtvc Literature 



For SaJe by all Laboratory Apparatus Dealers 

 Manufactured by 



The Thermo Electric Instrument Co. 



8 Johnson Street NEWARK, N. J. 



=APPARATU«: 



H-ION DETERMINATIONS SIMPLIFIED 



(2) A Portable, Precise Potentiometer 



^"^ is part of the Elliott- Acree Apparatus. It is a self-contained instrument, 

 operating on the Northrup Pyrovolter principle, and renders the complete outfit strictly 

 portable. Eeadings are given directly by deflections. One scale embodies pn values from 

 —1.5 to +15, and another values from 2 to 9, with a precision of 0.003 pn. The accuracy 

 is guaranteed to be within 0. 2 per cent, of full scale throughout the life of the instrument. 



1. Rapid, Sensitive Hydrogen Electrode 



3. Universal Buffer Solution 



4. Standard Buffer Tablets 



5. Exact Indicator Tablets 



Ask Us About The New Elliott-Acree Apparatus 

 PYROLECTRIC INSTRUMENT COMPANY 



Electrical Precision Instruments 



636-640 East State St. Trenton, New Jersey 



