2 I T: 
Congelation of jfj 'uichjilver in England. 
In my laft Paper I mentioned a freezing mixture, made by 
diffolving a powder compofed of equal parts of muriated am- 
monia and nitrated kali in water, and therein dire&ed fix parts 
of the mixed powder to be added to eight parts of water; but 
I have found fince, that the beft proportions are, five parts of 
the former to eight of the latter, by which I have funk the 
thermometer from ^o° to ii°. 
Having now profecuted my fubjedt relative to mixtures for 
generating artificial cold without the ufe of ice, from a poffible 
method propofed by Dr. Watson (Effays, Vol. III. p. 139.), 
for freezing water in fummer in this climate, and carried it on 
to a certain method of freezing, not only water, but even 
mercury, in fhe hotteft climate, I now intend to take my leave 
of it. 
I have the honour to be, &c. 
RICHARD WALKER. 
