7 
Ferric Oxide = 5*72 
Calcium ditto = 1 *9 1 
Magnesium ditto = 0'87 
Alkalies* (as Chlorides) — 3’ 6 9 
Organic Matter - 1*77 
Water = 7 ‘31 
100-49 
“ On the Decomposition of Calcium Sulphate by Alkaline 
Chlorides. A Contribution to Agricultural Chemistry/’ by 
M. M. Pattison Muir, F.RS.E. 
In one of his papers upon Diffusion, ‘f* Graham describes 
experiments which prove that a solution of potassium or 
sodium sulphate in lime water, when allowed to diffuse into 
lime water, yields a diffusate containing potassium or sodium 
hydrate : but that a solution of potassium or sodium chloride 
is not decomposed by lime water under the same circum- 
stances. Graham further shows that when solutions of 
calcium sulphate and potassium or sodium chloride are 
mixed no decomposition ensues at the ordinary tempera- 
ture, but that on boiling the mixed liquids for some time 
sulphate of sodium (or of potassium) is found, and continues 
to exist in the cold solution, inasmuch as if lime water be 
added two or three days after the boiling has been carried 
out, and the mixture be allowed to diffuse into pure water, 
caustic soda or potash is found in the diffusate. Graham 
suggests that if solutions of calcium sulphate and sodium or 
potassium chloride be allowed to react upon one another for a 
considerable period of time at ordinary temperatures, a 
decomposition might slowly take place analagous with that 
# The alkali consisted almost entirely of soda, The clay contained 
small quantities of phosphoric acid. 
f On the application of Liquid Diffusion to produce Decomposition ; 
Chem. Soc. J., III. 60. 
