65 
Ordinary Meeting, December 29th, 1874. 
E. W. Binney, F.B.S., F.G.S., Vice-President, in the Chair, 
“On a case of Reversed Chemical Action,” by James 
Bottomley, B.Sc. 
Having observed the solubility of iodine in a solution of 
borax, an experiment was made to see what the result of 
this solution would be, expecting to obtain a combination of 
soda with excess of acid, 27'8475 grins, of borax were dis- 
solved in about 250 grms. of water. As it was difficult to 
anticipate what the action of the iodine might be, this ele- 
ment was added at hazard, the quantity used being nearly 
seven grms. When assisted by heat almost the whole of 
this quantity dissolved in the solution, only a small quan- 
tity evaporating along with the aqueous vapour. The 
solution, which amounted to about 200 cc., had only a faint 
yellowish tint. Being set aside for some days, it deposited 
crystals which proved to be ordinary borax, for 0-5932 grms, 
of the crystals lost by heating 0*2773 grms. of water of crys- 
tallisation corresponding to 46*75 per cent, the theoretical 
quantity being 47*13. After removing the crystals the 
solution was still further evaporated in a retort. As the 
evaporation proceeded, instead of the faint yellow tinge 
disappearing as was anticipated, the colour of the solution 
began to darken, finally becoming opaque owing to the 
quantity of free iodine in solution ; vapours of iodine were 
also given off along with the steam. Thus the iodine which 
had previously dissolved and chemically united with the soda 
when the solution was dilute, was displaced and eliminated 
in the free condition when the mixture was past a certain 
degree of dilution. The explanation of this reversal of 
Prooeedino-s— Lit. & Phil. Soc. — Yol. XIY.— No. 6.— Session 1874-5. 
