\ 
ON THE DECOMPOSING POWER OF HOT STEAM. 193 
In obtaining.the alkalies from the chlorides of sodium and 
potassium, the patentee directs that the vapour of these salts, 
generated in an iron retort kept at a cherry red heat, with 
a current of steam playing on its surface, be passed through 
a vertical cylinder lined with magnesia and filled with small 
fragments of pure alumina, the whole being heated to a 
high red heat, with a current of steam entering below, and 
passing up slowly along with the salt vapour. The salt is 
decomposed in its passage through the alumina, its base 
uniting with that substance, whilst its acid is carried off 
with the excess of steam, etc. The complexity of this pro- 
cess has led to its complete modification, by the adoption of 
a plan of great simplicity, to be described presently. 
The patentee also obtains chromate of potash and soda 
by acting on a mixture of chrome ore with the sulphate or 
muriate of those bases, at a high temperature, with a cur- 
rent of steam and atmospheric air. The alkali, after be- 
coming free, reacts with the chromic acid formed by the 
contemporaneous oxidation of the oxide of chrome, forming 
chromate of potash, which is subsequently removed by 
lixiviation, &c. 
Soon after arriving in Europe, Mr. Tighlman applied to 
Professor Solly, of London, for his professional opinion in 
reference to his discoveries, and their application to the arts, 
and received in answer that they were perfectly new to him, 
unknown in Europe, and were fairly the subjects of pa- 
tents. Also that the objects are of great importance, and 
are likely to lead to many profitable improvements in our 
existing manufactures, as well as probably to create a num- 
ber of new ones. He acknowledges that the results com- 
municated by Mr. Tighlman depended on a new and hither- 
to unnoticed law in chemistry, the probable future influence 
of which can hardly at present be estimated. 
Subsequently, Prof. Solly gave a more formal opinion, 
founded on experimental researches, in reference to the pro- 
cesses, &:c., and fully endorsed his first opinion. 
