110 
ORIGINAL COMMUNICATIONS. 
funnel is intended to contain the nitric acid necessary for nitri- 
fication. The last part of the apparatus to be mentioned, is the 
steam boiler: this is of a low pressure kind, a half to one atmos- 
phere being all that is required; it sends off two leaden pipes, 
which pass, the one into the pipe of communication between 
the second and third chambers immediately before its termina- 
tion in the large chamber, and the other in a similar place in 
the pipe of communication between the third and fourth cham- 
bers; the orifice to allow exit for the steam is small; sometimes 
there is an additional pipe to the large chamber. 
To set this apparatus in operation, the burner is to be charged 
with the sulphur, the nitric acid put in the funnel, the floors 
of the chambers to be covered to the depth of two inches with 
dilute sulphuric acid, and the earthenware vessels charged 
with strong sulphuric acid. The acid in the chambers should 
be of different degrees of dilution ; in the first and second cham- 
ber strong; in the large, weaker; and in the last, weakest. 
The nitric acid is to be allowed to run slowly into the cham- 
ber, and the steam boiler is set in operation for about one hour 
or more, when the sulphur is to be ignited and the combustion 
regulated by means of the doors in the burner. The entrance 
of steam into the chambers is to be regulated according to the 
appearance at the end of the pipe of exit; when there is too 
much steam, a large quantity of white vapor passes out; when 
too little, a small quantity; and when in exact proportion, the 
fumes of nitrous acid are distinctly perceptible. 
The apparatus is kept in operation day and night without 
cessation. As soon as one charge of sulphur is burnt out the 
residue is withdrawn, and a fresh charge added, during which 
time the nitrification and steam is still kept in operation. 
The acid in the small chambers is allowed to run into the 
large one according to the strength of the acid in the former 
and the depth in the latter. When the acid has accumulated 
in sufficient quantity and of proper strength in the large cham- 
ber, it is withdrawn for concentration, which is performed in 
the usual manner. 
By this process every 100 pounds of sulphur yields 290 
