dissolved in the solution. The reaction was discovered in 1836 by a
Scotch chemist named John Thom, and small quantities of ammonia-soda
were made at that time by the firm of McNaughton & Thom. The successful
carrying out of the process on the large scale depends principally upon
the complete recovery of the expensive reagent, ammonia, and this
problem was only solved within comparatively recent years by Solvay. The
process has been perfected and worked with great success in England by
Messrs. Brunner, Mond, & Co., and has proved a successful rival to the
Leblanc process.

Alkali is also produced to some extent by electrolytic processes,
depending upon the splitting up of a solution of common salt into
caustic soda and chlorine by the use of an electric current.




LECTURE VI

BORIC ACID, BORAX, SOAP


_Boric Acid._--At ordinary temperatures and under ordinary conditions
boric acid is a very weak acid, but like silicic and some other acids,
its relative powers of affinity and combination become very much changed
at high temperatures; thus, fused and strongly heated boric acid can
decompose carbonates and even sulphates, and yet a current of so weak an
acid as hydrogen sulphide, passed through a strong solution of borax,
will decompose it and set free boric acid. Boric acid is obtained
chiefly from Italy. In a tract of country called the Maremma of Tuscany,