402 Reviews, and Notices respecting New Books. 
If, however, it be an electrolyte, which is very improba- 
ble, it will be a proof that in the electrolyzation of a sub- 
stance the evolution of the one ion depends entirely on the 
nature of the other ion with which it is combined; and thus 
the terms anions and cations will only be relative. If, how- 
ever, iodic acid is not electrolyzed, still this experiment fur- 
nishes us with another exception to the law of liquido-con- 
duction * similar to the periodide of mercuryt+. 
22. Unfortunately, however, iodic acid is decomposed b 
the same degree of heat which is required to melt it, and the 
vapours of iodine entirely prevent the acid being examined 
during the experiment: it is also decomposed by almost all 
substances which can be used as electrodes, and therefore the 
advantage which can sometimes be taken of observing which 
of the electrodes is corroded, is here of no avail. I was there- 
fore quite unable to ascertain whether iodic acid was electro- 
lyzed or not; but when the electrodes were immersed in the 
fused acid, much stronger ebullition seemed to take place than 
before. 
23. It was impossible to ascertain whether the oxides of 
bromine and chlorine were conductors or not, and I therefore 
had not the advantage of comparing iodic acid with the bro- 
mic and chloric acids. 
I had at first some hopes of being able to add further ex- 
periments in relation to these last described, but finding that 
not in my power, I no longer delay sending the above. 
7, Curzon Steeet, 15th April, 1836. 
LXXIII. Reviews, and Notices respecting New Books, 
On the Theory and Solution of Algebraic Equations ; with the Recent 
Researches of Budan, Fourier, and Sturm on the Separation of the 
Real from the Imaginary Roots of Equations: by J. R. Youna, Pro- 
fessor of Mathematics in Belfast College. Souter, London. 
We have more than once dwelt upon the remarkable perspicuity 
; of Mr. Young’s writings. In this respect they are, one and all, 
models of the very best kind for the elementary writer, and far better 
adapted than any which we are acquainted with, for the purposes of 
actual study. In saying this, we mean no ordinary praise ; for of all 
kinds of writing on science, and especially on mathematical science, 
the development of elementary principles in a perspicuous and logical 
manner is the most difficult. If Mr. Young had succeeded only in 
this, beyond any other author in our language, he would have achieved 
much, and have effected sufficient towards a diffusion, not only of 
* Exp.Res. in Electricity, by Mr. Faraday, No.402.—[Lond. and Edinb 
Phil. Mag., vol. iii.] 
¢ Ibid. No. 691.—[vol. v. p. 169.] 
