398 



CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 



No. 10270. No. 10272. 



No. 10274. 



Nos. 10278-9. 



Nos. 10282-3. 



No. 10286. 



No. 10292. 



No. 10294. 



10270. ELECTRODE, Gas, Hasselbalch, for use in Hydrogen Ion determinations. With ground in stopper 

 carrying binding post ana platinum electrode, two side tuoes with glass stop-cocks, and siphon 

 tube with glass stop-cock $15.00 



10272. ELECTRODE, Gas, Hildebrand, with S-shaped platinum electrode so situated that half its surface 

 is immersed, the other half exposed to the gas. "With side tube for introduction of gas. (See 

 Journal of American Chemical Society, Vol. XXXV, No. 7, for July 1913, page 850) 7.50 



10274. ELECTRODES, Gas, Long, simple form for use in determining the Hydrogen Ion Concentration 

 in urine, blood, etc. Complete with two glass cells with rubber stoppers and platinum elec- 

 trodes, mounted on wooden stand as illustrated, without clamps or rubber tubing 8.00 



10278. ELECTRODE, Gas, Ostwald, with gas introduction tube, siphon tube with glass stop-cock, and 



gas exit tube with trap to prevent entrance of air, but without platinum electrode. . . . 4.00 



10279. ELECTRODE for No. 10278, with platinum foil attached to glass tube inserted in rubber. stopper. 



Weight of platinum, about 1.2 grams 7.50 



10280. ELECTRODE for No. 10278 with platinum deposited on glass tube inserted in rubber stopper, and 



with internal contact, according to Luther 2.50 



10282. ELECTRODE, Gas, Ostwald-Luther, similar to No. 10278, but with longer gas introduction tube, 



siphon adjustable in height, and with ground in tubulation to take electrode, but without 

 electrode 5-00 



10283. ELECTRODE for No. 10282, with platinum deposited on glass tube and with rubber stopper to fit 



tubulation 2.50 



10286. SUPPORT for Calomel and Gas Electrodes, consisting of a heavy non-corrosive metal base and 



rod with clamp to hold glass cells 2.75 



HYDROGEN ION DETERMINATION APPARATUS. For the determination of the Hydrogen 

 Ion Concentration by means of Gas Electrodes Nos. 10270 to 10283, we recommend the use of 

 our No. 10436 Conductivity Bridge together with a Calomel Electrode (No. 10242 to 10250), one 

 of our Resistance Boxes (see Nos. F4701 to F4722), our No. F4465 Portable Galvanometer, and 

 an appropriate source of current. A Capillary Electrometer (Nos. 10292 to 10298) can be used 

 if desired instead of a Galvanometer. 



10292. ELECTRODE TUBE, Capillary, Lippmann, horizontal form, without electrodes 60 



10294. ELECTRODE TUBE, Capillary, Luther, filled, exhausted and permanently sealed, with platinum 

 contacts sealed in 3.00 



