4 Dr. Bottom ley on the 



most interesting M.S. was rescued from destruction during 

 a general clearing out of old papers stored in the cellars of 

 the old East India House in Leadenhall Street, London, by 

 Mr. Melvill's grandfather, the late Sir James Cosmo Melvill, 

 K.C.B., F.R.S., secretary of the H.E.I.C.S. for many years, 

 from whom Mr. Melvill inherited it. 



On the possible equations expressing the decomposition 

 of Potassic Chlorate by Heat. By James Bottomley, 

 D.Sc, B.A., F.C.S. 



It has long been known that potassic chlorate when 



heated is resolved into oxygen, potassium chloride, and a 



more highly oxygenated product, potassium perchlorate, 



the equation expressing the change being usually written 



2KCIO3 = KCIO4 + 2KCI + O2. 



Lately the decomposition of the salt has been investi- 

 gated by Teed, and also by P. Fraiikland and Dingwall, 

 their results being communicated to the Chemical Society. 

 Teed, from his results, derives the equation 



10KCIO3 = 6KCIO4 + 4KCI + 3O0, 

 and in a second communication giving the results of ex- 

 periments wherein the salt was more gently heated, he gives 

 as a more approximate equation 



22KCIO3 = 14KCIO4 + 8KC1 + 5O2, 

 P. Frankland and Dingwall derive from their results the 



equation 



8KCIO3 = 2O2 + 5KCIO4 + 3KCI. 



The matter has also been discussed by Mills in the 



April number of the Philosophical Magazine. He there 



gives the following equation as expressing all known 



relations among those products : — 



(i) 2;2KC103 -in- 2)02 = {n + i)KCl04 + {n - i)KCl. 



Some years since I gave a general method for determining 



the coefficients in chemical equations (^Proceedings — Lit. 



