332 



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



No. 8214. 



No. 8220. 



No. 8222. 



No. 8226. 



No. 8230. 



No. 8234. 



8214. LAMP, DAVY'S SAFETY, as used in mines. Height, about 25 cm $4.00 



LANTERNS, Projecting, see Catalog F of Physical Apparatus. 

 8216. LEAD SHOT for cleaning bottles, etc. 



Size No 4 6 7 8 11 



Per pound 20 .20 .20 .20 .20 



F2857. LEATHER BELTING, Round. 



Diameter, inches % % 2 % 6 



Per foot 10 .12 .18 



LECTURE APPARATUS 



8220. LECTURE APPARATUS, for Electrolytic Decomposition of Water, simple form with sliding 

 graduated tubes and removable carbon electrodes 3.50 



8222. LECTURE APPARATUS for Electrolysis of Water, improved form, with platinum electrodes 



that may easily be replaced by copper electrodes or by carbon electrodes for electrolysis of 

 hydrochloric acid. (See Nos. 8*238 and 8239.) Complete with support ' 6.80 



8223. GLASS PARTS only of No. 8222 3.80 



8226. LECTURE APPARATUS, Hoffman's Form, for electrolysis of water, hydrochloric acid, and 



ammonia, with ungraduated tubes, two stop-cocks and platinum electrodes, mounted on sup- 

 port as shown 11.50 



8227. GLASS PARTS only of No. 8226 with platinum electrodes 8.50 



8230. LECTURE APPARATUS. Hoffman's Form, same as No. 8226 but with tubes graduated to show 



volumetric composition. Complete with support 13.50 



8231. GLASS PARTS only for No. 8230. 10.50 



8234. LECTURE APPARATUS, Hoffman's Improved Form, for decomposition of water, with gradu- 



ated tubes, glass stop-cocks and removable platinum electrodes, complete with support 13.00 



8235. GLASS PARTS only for No. 8234 with platinum electrodes 10.00 



8238. CARBON ELECTRODES for use with Nos. 8220, 8222, 8234 and 8268, consisting of two rubber 



stoppers fitted with carbon electrodes .60 



8239. COPPER ELECTRODES, same as No. 8238, but with copper instead of carbon electrodes .60 



8240. PLATINUM ELECTRODES, same as No. 8238, but with platinum instead of carbon elec- 



trodes 2.75 



8242. SUPPORT STAND only for Nos. 8222, 8226, 8230 and 8234 with binding posts 3.00 



8246. LECTURE APPARATUS, Hoffman's Form, for showing volumetric composition of hydrochloric 



acid, with two stop-cocks, complete with support, as illustrated 10.80 



8247. GLASS PARTS only of No. 8246 5.00 



8250. LECTURE APPARATUS, Hoffman's, same as No. 8246, but with platinum electrodes, for dem- 



onstrating the volumetric synthesis of ammonia and water. Complete with support. . 8.50 



8251. GLASS PARTS only of No. 8250, with platinum electrodes 5.50 



8254. LECTURE APPARATUS, Hoffman's Eudiometer, similar to No. 8250, with platinum electrodes, 



two stop-cocks, and graduated arm. Complete with support 13.00 



8255. GLASS PARTS only of No. 8254, with platinum electrodes 10.00 



8258. LECTURE APPARATUS for Decomposition and Synthesis of Water, similar to No. 8250, but 



with platinum electrodes in middle of closed tube. Complete with support 11.50 



8259. GLASS PARTS only of No. 8258, with platinum electrodes 8.50 



8262. LECTURE APPARATUS, Hoffman's Form, for demonstrating the fixed proportions in the com- 



bination of hydrogen and chlorine to form hydrochloric acid. With glass stop-cock, ground 

 stopper, and support stand 6.50 



8263. GLASS TUBE only of No. 8262, with ground stoppers and stop-cock 4.00 



Note: For illustrations of Nos. 8246-62, see next page. 



