of Edinburgh^ Session 1864-65. 413 
probably depends on the ‘‘'chemical position” of the alcoholic 
water residue in the molecule. 
Eecollecting that benzoic aldehyd has been prepared from ben- 
zoic acid by Piria and by Chiozza, we see that by three* processes, 
Is^, the subtraction of oxygen ; 2d, the addition of the elements of 
formic acid ; and, 3d, the subtraction of oxygen, we have advanced 
one step in the homologous series of the aromatic acids ; and, as far 
as we can see, there is nothing to prevent the repetition of this 
step, and the gradual ascent of the series. 
With a view to ascertain whether this is possible, I ]jave treated 
cuminol with hydrocyanic and' hydrochloric acids, and the results 
obtained are sufficient to encourage me to continue the investigation. 
7. On the Nature of Antozone. By Alfred K. Catton, B.A., 
F.E.S.E., Fellow of St John's College, Cambridge, and 
Assistant to the Professor of Natural Philosophy in the 
University of Edinburgh. 
Many of the properties of ozone are very similar to those of per- 
oxide of hydrogen. Thus ozone, like peroxide of hydrogen, is in 
many cases a powerful oxidising agent. In other cases, however, 
it acts as a deoxidiser. Thus ozone deoxidises peroxide of hydro- 
gen and peroxide of barium with the production of water and oxide 
of barium. Peroxide of hydrogen also deoxidises oxide of silver, 
the peroxides of manganese and lead, permanganic and chromic 
acids, &c. Again, ozone is decomposed catalytically by dry silver 
leaf and by several oxides, such as the peroxides of manganese and. 
lead, &c. Peroxide of hydrogen is also decomposed catalytically by 
several metals — gold, silver, platinum, and metallic oxides. Ozone 
liberates iodine from a solution of iodide of potassium. Peroxide of 
hydrogen does the same by the mere addition of a few drops of proto- 
sulphate of iron, the latter undergoing no change during the reaction. 
We see then that the general properties of ozone are very similar 
to those of peroxide of hydrogen. If, however, we examine the 
properties of these compounds in detail, we find that their particular 
properties are complementary to each other. In other words, for 
the particular compounds for which ozone acts as an oxidising 
agent, peroxide of hydrogen does not act as an oxidising, but in 
