TRANSACTIONS OF THE SECTIONS. 4f 



gases are dissolved in the liquid as quickly as they are formed, if the poles, whether 

 they be large or small, be freely exposed to the action of a large mass of the liquid ; 

 but if the bulk of liquid around each pole be made to correspond to the volume of 

 the gases evolved, the latter will not be dissolved to a greater extent than in ordinary 

 eudiometric experiments conducted over water. To attain this object it is only ne- 

 cessary to employ thermometer tubes, having fine platina wires hermetically sealed 

 into their upper ends, as the tubes for receiving the gases. The wires may be so long 

 as to extend through the entire length of the thermometer tubes ; but it will be suffi- 

 cient if they only project a short way into the tubes, as the film of liquid which covers 

 the interior of the tube is sufficient to conduct electricity of such high tension as that 

 produced by the electrical machine. 



That the gases were evolved very nearly in the proportion of 1 vol. oxygen to 

 2 vols, hydrogen, will appear from the following examples : — 



Hydrogen 6-85 4-00 3-35 



Oxygen 3-45 2-10 1-55 



The electrolyte employed in these experiments was water containing 1 per cent, 

 of sulphuric acid. The gases collected in these tubes were thus proved to be oxygen 

 and hydrogen : — 



1. Electrical sparks passed through the hydrogen tube exhibited the characteristic 

 red colour which electrical flashes produce in that gas. 



2. On introducing a solution of iodide of potassium into the oxygen tube, and 

 passing sparks through it, the oxygen was converted into ozone, and absorbed in the 

 course of about one minute. 



3. On reversing the connexions with the electrical machine and the ground, the 

 relative volumes of the gases were reversed; and after passing the current for the 

 same time as before, and afterwards a spark through the mixed gases, they combined 

 together in both tubes with explosion. 



Each of the above divisions contained 0'00006 cent, cub., and an electrical machine, 

 in good order and performing 240 revolutions each minute, produced about I'l divi- 

 sion of oxygen gas in the same time. A column of acidulated water, 10 feet long, 

 and having a section equal to the internal calibre of a fine thermometer tube in which 

 it was contained, presented no sensible resistance to the passage of this cuiTent ; but 

 a similar column of distilled water 1 foot in length reduced the current to -^th of its 

 original amount. 



On passing the electrical current through a series of sixty pairs of thermometer 

 tubes charged with acidulated water, and fitted with platina wires as already 

 described, decomposition proceeded with the same facility, and the same amount of 

 oxygen and hydrogen was collected in each pair of tubes as when only a single 

 couple was interposed in the circuit. 



The same apparatus enabled me to decom.pose water without difficulty by means of 

 atmospheric electricity. To collect the electricity, I employed an electrical kite which 

 carried a fine brass wire attached to its cord. The experiments were all performed 

 on fine clear days, when the air exhibited no unusual symptoms of free electricity. 

 On connecting the platina wire of one of the thermometer tubes with the insulated 

 wire of the kite, and that of the other tube with the ground, the decomposition pro- 

 ceeded slowly but steadily at the rate ofO'9 div. or about 0000054 cub. cent, oxygen 

 per hour. Hence about O'OOOOOOOSS gramme water was decomposed hourly, or nearly 

 Tbooooob gramme, or tooVob^ °f ^ grain. The wire of the kite gave small sparks, 

 varying in length according to the amount of movement in the kite, from one-tenth to 

 half an inch in length. The shocks were moderately strong ; and the needle of a 

 galvanometer of 2000 coils was sensibly deflected. 



In the Philosophical Transactions for 1831, Mr. Barry describes an experiment, 

 in which he supposes that he collected the gases produced by the decomposition of 

 water by the action of atmospheric electricity; but from the form of apparatus which 

 be employed, I consider it very improbable that he could have succeeded in collecting 

 any visible quantity of either of the gases. 



