78 
Subjoined are the results of a few of the experiments on 
iron wire. 
QUALITY. 
No. 
ELONGATION. 
BREAKING STRAIN. 1 
1 
Immersed in 
Acid 1 Hour. 
Heated. 
Immersed in 
Acid 1 hour. 
Heated, i 
Annealed Iron 
r 
1 
15% 
22% 
1176 
1168 
Wire, 1 
2 
19 
20 
1176 
1162 
•164in. diam. ( 
3 
22 
19 
964 
1008 
Average 
18-6% 
20-3% 
1105-3 
1112-6 
4 
24% 
22% 
908 
944 
5 
24 
21 
908 
930 
6 
22 
25 
896 
946 
Annealed Iron 
7 
21 
23 
914 
908 
Wire, -i 
8 
22 
22 
926 
924 
•150in. diam. 
9 
24 
24 
926 
924 
10 
22 
23 
934 
896 
11 
22 
21 
930 
928 
V 
12 
21 
20 
924 
906 
Average 
22-4% 
22-3% 
918-4 
922-8 
Hard Iron 
13 
•5% 
2% 
1230 
1218 
Wire, -j 
14 
2-5 
3'5 
1146 
1230 
’136in. diam. 
15 
2 
3 
1200 
1232 
Average 
2% 
2-83% 
1192 
1226-6 
IV. — Effect of Pyroligneous Acid. 
The effect of pyroligneous acid on iron and steel appears 
to be exactly similar to that of hydrochloric and sulphuric 
acids, causing it to become more brittle, &c., though the 
• effects are perhaps somewhat less intense. As in their case, 
heat restores the iron to its original toughness. 
Y . — • Effects of Acids on Copper and Brass. 
Sulphuric acid appears to have no effect whatever on 
copper. After 18 hours’ or longer immersion in sulphuric 
acid copper is as tough as ever, the action being confined to 
the surface onlv. 
«/ 
Brass becomes rotten after long immersion in vitriol, 
doubtless because the zinc of which it is partly composed is 
attacked by the acid, and, as might be expected, heat does 
not restore it to its original condition. Prolonged exposure 
to a moist damp atmosphere appears to make brass brittle 
just as acid does. 
