10S 
ORIGINAL COMMUNICATIONS. 
indicated by these experiments. The bark of the Dittany 
contains: vegetable albumen, gum, starch, sugar, resin, 
EXTRACTIVE MATTER, A COLORLESS FATTY OIL, WOODY FIBRE, 
SALTS OF POTASSA AND LIME, AND IRON. 
ART. XVI.— ON THE MANUFACTURE OF SULPHURIC ACID. 
For several years past some manufacturers of France and 
England have been using a different process for procuring 
sulphuric acid than that which has hitherto been practised. 
As we have not as yet seen any published notice of this 
method, we have thought that such information as we have 
been able to obtain from those who have seen this process in 
operation, would not be unacceptable to our readers. 
The principal materials used in this method are sulphur and 
nitric acid aided by sulphuric acid and steam. The process is 
conducted in a suite of chambers (five or more) lined with 
lead. The only apparatus of which we have seen any diagram 
consists of live chambers of such a size as to produce 2900 lbs. 
of concentrated acid per diem. Four of the chambers are of a 
small size, and the other very large, and arranged to suit the 
convenience of the manufacturer in the following order. First, 
two of the smallest chambers, next the large chamber, and finally 
the other two, which are somewhat larger than the first, the 
smaller chambers being elevated to the ceiling of the largest. 
Outside and near to one of the smallest chambers is to be 
placed a burner or vessel for the combustion of the sulphur, 
sufficiently large to hold the daily charge requisite for the 
supply of the chambers. This burner communicates with 
a small chamber by means of a large pipe which enters 
near the ceiling; this chamber then communicates with the 
next small chamber by means of a large pipe which com- 
mences near the bottom of the first, and ascends and termi- 
