f 548 1 



The fused luelallic antimony was poured into cvliiiders ot'asl)ostos 

 paper tied round witli ('oj)per wire: llie rods of antimony tiius formed 

 were cleansed \\illi liydrocliloric acid and waslied. 



By way of control we dissolved a piece A\ei!j;liin:L!,' 20 üi-ams in 

 pure stron<i' Jiilric acid witii addition of 7.5 grams of crystals of 

 tartaric acid. 'Die clear acid solution so obtained was rendered ali<aline 

 l>y addinii' small lumps of sodium hydroxide prepared from metallic 

 sodium (the lye was free from foreijiii metals) and digested on the 

 Avaterhath with a clear solution of sodium sulphide hiit ga\e no 

 precijiitate. 



The soluti(tns wei-e prej)ai"ed l>y ^\eig•hing the pure» antimony 

 ti-ichloride roughly and dissolxing the same in pure hydi-ochloric aci<l 

 of 1.12 sp. gr. at lo°. The exact composilion of the solutions was 

 determine*! I>y electrolysis of the Ii(prKl in j)i"('s(Mice of sodium sul- 

 phide accordijig to Nkimann's directions' . 



4. In each exjjeriment two silver coulometers were put into the 

 circuit; one in front and oiie behind the series of antimony solutiojis 

 which took })art in the electrolysis. The coulometers consisted of 

 200 cc. platinum dishes with i-ongh inner surfaces. We will not 

 fnnit to point out that such dishes ai'e j)arlicularly suited for coulo- 

 metric determinations as il is |)ossil)le to preci[)itate in them a large 

 amount of silver with lilllc chance of any traces being detached on 

 washing the j>r(M'ipitates -'). 'ïho amount of siher deposited in our 

 experiments varied from 25 to 50 grams whilst when using the smooth 

 dishes usually em[)loyed it is diiKicult to handle a few gi-ams without loss. 



As electrolyte we used a 10 or J 5 per ceid neutral solution of 

 siher nitrate; jio dilference was noticed with these solutions. The 

 [)0sitive silver plates were cast of silvei- which we I'eceived from 

 ])i-. HoiTsi'.MA, (\)in|>ti-oller-general at the local Government .Mijit. 

 On analysis, we could not trace foreign metals in 100 grams of this 

 silver. The plates were 0.5 cm. in diameter an<l 4 mm. thick. 

 They were surrounded by a co\(M-ing of titter paper (Schlkichkr and 

 Schlll). Each silver ])late was susj>ended by a thick platinum \vire. 

 The coulometer dishes after being filled with the silver solutioJi wei-e 

 covered with a glass plate with a hole in the centre through which 

 a platinum wire was introduced. 



2) Analytical Electrolysis of Metals. Halle 18'.>7. S. 145. 



Here, we provisionally took the atomic weight of antimony lobe 120; as will be 

 seen from what follows, llie uncertainty of the atomic weight is of no consequence here. 



-) Compare Kahle. VVikd. Ann. 07, N.F. 1 (1899); Richards, Collins and Heimrod, 

 Proc. American Acad, of Arts and Sciences XXXV, \'23 (1899). Puchauds and 

 Heuirod, Zeilsclu-. f. i)iiysikalische CUeniie 41, 302 (1902). 



