ON ELECTROLYSIS IN ITS PHYSICAL AND CHEMICAL BEARINGS. 397 



The hydrochloric acid solution was then diluted with an equal volume of water, 

 making its sp. gr. 1'030. A test-tube was filled with this and inverted over the 

 baric chloride solution. There was no visible mixture ; the place where the two 

 liquids met remained quite sharp. 



October 30, 1885. — A tube of uniform cross section and '41 centimetre internal 

 diameter was taken and bent as shown in fig. 3. Its total length was 84*2 centi- 

 metres. This tube was marked No. I. 



It was filled with hydrochloric acid solution, of specific gravity 1*030, slightly 

 tinged with litmus. 



Two vessels containing the 1'093 solution of Na.,SO^ and BaCl, respectively 

 were arranged with vertical sticks of electric-light carbon as electrodes, and their 

 levels as carefully adjusted as possible. The final adj ustment was performed by a 

 short siphon tube with a pinch-cock in the middle, and full of hydrochloric acid of 

 sp. gr. 1'093 (see fig. 3). The experimental tube No. I. was then introduced very 

 carefully at xiv. hrs. 58 min. At xv. hrs. 2 min. the pinch-cock of the levelling tube 

 was closed, and the current started, flowing from BaCl., vessel to Na^SO^ vessel. 

 Current strength '01 ampere. 



October 31. — Noon : ring beginning to form 



22 centims, from NaoS04 end, and " 

 62-2 „ „ BaCUend. 



November 2, 1885. — Another similar experiment with same tube. Levelling 

 tube started at xi. hrs. 49 min. Experimental tube put in xi. hrs. 55 min. Levelling 

 tube closed at xii. hrs. 2 min., and current started of strength '01 ampere. 



By November 3, at ix. hrs. 47 min., ring formed ; and at xiv. hrs. the current was 

 stopped. Strength, -007 ampere. 



Solutions then tested and found all right ; apparently a satisfactorj^ experiment. 

 Distance of ring 



from Na„SO^ end 24-6 ; 

 „ BaCl, „ 59-6. 



November 3. — Another experiment started with the same tube ; fresh liquids 

 still with density 1-093 for BaClj and Na^SO^, the HCl (coloured with litmus) of 

 density 1-030. Levelling tube put in at xiv. lars. 30 min. ; experimental tube at 

 xiv. hrs. 34 min. Levelling tube closed and current started at xiv. 36 min. Strength 

 of current, -009. 



On November 4 at x o'clock the ring was formed. 



Distance from Na^SO^ end 31-8 centims. 

 „ Bad, „ 52-4 „ 



Novembei- 4. — Similar experiment, except that the tube is filled with an un- 

 coloured solution of HCl of ordinary testing strength, that is, one centigramme 

 molecule in 5 cc. Average cuiTent strength, -009. 



. Distance of ring from NajSO^ end 16-8 centims. 

 „ BaCl, „ 67-6 „ 



November 6. — Another experiment with the '01 HCl is 5 cc. Current strens-tk 

 •009. 



Distance of ring from Na2S04 end 16-4 ; 

 „ „ BaClj „ 68-0. 



November 7. — A blank experiment arranged purposely with no current. Tube 

 put in and levelling tube closed at xiii. hrs. 35 min. 



By November 10 there was no ring formed and no deposit anywhere in the tvhe. 



November 24. — Two other similar tubes prepared, each of the same internal 

 diameter — -41 centims. — but of lengths, No. II. 87 centims., No. III., 88-4 centims. 

 The three tubes were then filled with the HCl solution ("Ol in 5 cc), and arranged 

 with three pairs of vessels in multiple arc. The result was that, while the 

 precipitate occurred in tube I. in about its usual position, in tubes II. and III. 

 it occurred quite at end of the tube where it dipped into the Na.jSO^ vessel, and 

 accordingly most of it fell out of the tube. 



