Intelligence and Miscellaneous Articles, 471 



addition of soluble starch, which by the sudden blue coloration 

 indicates the liberation of iodine. 



Solutions were used containing 0*25 gr. of iodic acid in a litre 

 of water, or the same quantity in the litre of a mixture of equal 

 parts of glycerine and water. 



The sulphurous acid was used of such concentration that 5 cub. 

 cent, of its solution in water just decolorized 2 cub. cent, of a 

 one-per-cent. solution of potassium permanganate. 



On mixing 10 cub. cent, of solution of iodic acid with 3 cub. 

 cent, of sulphurous acid, the reaction sets in in about 5 minutes, and 

 in the various glass vessels shows an inert space above, which lasts 

 for a time depending on the temperature. 



The iodine reaction presents a phenomenon to which I shall 

 afterwards recur ; that is, the occurrence of this reaction in the 

 centre of the tube. If a vertical glass tube 4 millim. in the clear 

 is filled by aspiration, and subsequent closing by an indiarubber 

 tube and clamp, from the active liquid which is contained in a wide 

 glass cylinder, a fine blue thread is seen to form in the tube, while 

 the surrounding liquid remains clear and colourless. The blue 

 coloration extends gradually from the thread throughout the entire 

 liquid column. 



It could be observed in this phenomenon that the reaction in the 

 wider vessel set in sooner than in the narrow tube. 



If either the hydrate-of -chloral or the iodic-acid mixture is placed 

 in a vessel in which the liquids can be drawn through fine glass 

 beads, no chemical reaction at all is produced. 



It follows thus from these experiments : — 



1. That in liquids the space of chemical action is bounded by an 

 inactive zone {the inert space), where the liquid is in contact with 

 the air, or is separated from it by a fine membrane. 



2. That the reactions take place more slowly in narrow than in 

 wide tubes. 



3. That capillary spaces can entirely suspend chemical reactions. 

 As I am engaged in continuing this investigation, I hope soon, 



after a further extension of the experiments and the use of other 

 chemical reactions, to be able to report fresh results. — Berliner 

 Sitzunrfsberichte, November 4, 1886. 



APPARATUS FOR THE CONDENSATION OF SMOKE BY STATICAL 

 ELECTRICITY. BY H. AMAURY. 



A glass cylinder is placed on a tripod perforated in the centre, 

 and below it a tin-plate box with an opening in the side and at 

 the top, in which touch-paper, tinder, or tobacco can be burned, and 

 thus the cylinder be filled with smoke. To the top of the cylinder 

 is fitted a small lid in which is a vertical tube. At half the height 

 of the cylinder are two diametrically opposite tubuli, through which 

 pass metal rods ; these are connected with vertical rods parallel to 

 the sides and provided with points. If these combs are connected 

 with the conductors of an electrical machine, and the latter is 

 worked, the smoke is condensed. — Beiblatter tier PhysiJc, No. 2, 1887. 



