Sulphuric Acid-manufacture. 



33 





The ordinary funnel-shaped collector usually placed in the 

 chamber, and which communicates with a small leaden jar on 

 the outside, by which a manufacturer gets an idea of the strength 

 and make of his acid, was brought into use. Instead of being, 

 as usual, placed about 8 feet from the bottom of the chamber, it 

 was in this case placed about 16 feet high, and the amount of 

 sulphuric acid formed was carefully observed. 



In this case, after standing nine days, only T ^- of an inch of 

 acid had formed, whilst at the height of 4 feet the make of acid 

 was regular and fairly large. 



In the former case (at 16 feet) sulphurous acid was continu- 

 ously escaping, whilst the amount in the latter was merely tri- 

 fling. This, then, was a very fair proof of the truth of my theory. 



Sulphuric Acid, 



Passing from the sulphurous to the sulphuric acid, I find the 

 diagram of percentage in the latter a very strange one. At 10 

 feet from the point of entrance, where is the percentage of 

 acid, to 140 feet the variation at 15 feet in height is very trifling. 

 The highest amount is reached at 50 feet, showing there only 

 23 per cent. But at 3 feet the analyses present a more extra- 

 ordinary difference than that of Diagram I. 



Beginning again at 10 feet from entrance, I find the amount 

 of acid to be equal to 81 per cent. ; then a sudden rise brings it 

 to 89 per cent., this being the maximum ; then comes a most 

 rapid and continuous fall, till at 100 feet the amount is 30 per 

 cent., and remains nearly at this to the end of the chamber. 



The following diagrams will show the variations. 



[Diagram II a, see p. 34.] 



Diagram lib. 













Length of chambei 



', in feet. 











(Entrance.) 



10 20 30 40 50 60 70 80 90 100 110 120 130 140 



15 feet inl 

 height. J 



p.c. 

 



p.c. 

 



p.c. 

 6 



p.c. 

 18 



p.c. 

 23 



p.c. 

 20 



p.c. 

 18 



p.c. 

 16 



p. c. 

 19 



p. c. 

 12 



p.c. 

 12 



p.c. 



7 



p.c. 



7 



p.c. 

 10 



\ feet in \ 

 height. J 



p.c. 

 8i 



p.c. 

 89 



p.c. 



76 



p.c. 



70 



p.c. 

 68 



p.c. 



67 



p.c. 



60 



p.c. 

 56 



p.c. 



48 



p.c. 



30 



p.c. 



38 



p.c. 



30 



p.c. 

 36 



p.c. 



33 



(Exit.) 



15 feet in 

 height. 



3 feet in 

 height. 



Length of chamber, in feet. 

 The figures in the divisions of the above diagram represent 

 Phil. Mag. S. 4. Vol. 45. No. 297. Jan. 1873. D 



