PRODUCTION OF SULPHURIC ACID. 11 
the absorption bulbs (D, D’, D’’) containing strong nitric acid, 
which absorbed the sulphur dioxide escaping oxidation in the spiral. 
The quantities of sulphur dioxide converted into sulphuric acid in 
the tube (A) and the spiral (B), as well as that which escaped oxida- 
tion and was subsequently absorbed in the bulbs (D, D’, D’’), were 
determined by analyses. The results of these analyses are given in 
Tables IT and III. 
When the lead spiral was used (Table II), the amount of sulphuric 
acid formed therein had to be determined by difference because of 
the formation of lead sulphate, which could not be entirely removed 
from the tube by washing. 
On account of the many joints and rubber connections necessary 
in the apparatus there was some loss of sulphur dioxide in the sys- 
tem. When the lead spiral was used, the amount of this loss could 
not be determined, so all the errors occurring in Table II are thrown 
into column 5, making the figures for the sulphur dioxide oxidized 
in the lead spiral larger than they actually should be. 
TaBLE II.—Sulphur dioxide oxidized to sulphuric acid in apparatus shown in figure 1. 
Lead spiral used and steady stream of oxides of nitrogen furnished throughout experiments. 
SOe oxidized in 
system. 
Time of | Rate per a SOz2 lost Oe 
Number of run. ees (eHOUrOr i and 
SO2 | tn vessel| Inlead | SYSt€™-"| of spiral. 
spiral B. 
Hours. Grams. | Per cent. | Per cent. Per cent. 
Ey ee Seniesa nt rete ge tes Pence MRS SM ea 2 6. 2017 32.07 GOD eg eee ae 0.01 
Ie ee REG AO pete EEE NC SECS 2S 2 6. 4887 26. 61 MSTOO [oars Trace. 
ee are eee en ere aha: fine ier aes eben eee tan 2 7. 6569 23.00 OS OOM ae ee eae -O1 
1 Could not be determined. Included in the figures in column 5. 
An inspection of Table II shows that by passing sulphur dioxide, 
_ air, and water vapor through a lead spiral in the presence of an 
adequate supply of the oxides of nitrogen, the formation of sulphuric 
acid is practically complete, even when the gases are run at quite a 
rapid rate. 
- In ordinary ¢hamber plants it is considered very good practice if 
only 10 feet of chamber space is required for every pound of sulphur 
burned in 24 hours. Figuring the chamber space required in run 
No. 8, it is seen that for every pound of sulphur burned in 24 hours 
only 0.139 foot of chamber space was required. 
While it is hardly fair to compare the results obtained in the 
laboratory with those obtained on a factory scale, still the efficiency 
of the apparatus can be more readily judged by expressing the results 
in the conventional way. 
The well-known characteristic of some metals, as well as metallic 
oxides and salts, of acting as catalytic agents made it seem possible 
