THE ACTION OF CHEMICAL AFFINITY. 
189 
The regularity of this increase of colour (as exhibited to the eye in the curves) is a 
proof that no law obtains under the circumstances of the experiment, similar to that 
observed and enunciated by Bunsen. There is nowhere any sudden increase in the 
amount of ferric sulphocyanide formed. If the partition of the bases and acids in the 
mixture really take place at first in atomic proportions, it is evident that, being at full 
liberty to act and react, the salts arrange themselves according to their respective 
mass, without reference to their respective atomic weights. 
The effect of mass on the formation of ferric sulphocyanide in a mixture of salts, 
where other substances replaced the nitric acid or the potash, was also tried. 
Two solutions were prepared, each containing 50 gr. meas. of the ferric sulphate 
mixed with 12‘5 gr. meas. of sulphocyanide of potassium, and the experiment was 
conducted as in the former instances. The weakness of the colour produced when a 
sulphate is present was the reason why the amount of the salts employed was doubled . 
The following are the results deduced from the observations : — 
Fe™ sulphate. 
Red salt 
produced. 
FetHe sulphate. 
Red salt 
produced. 
1 equiv.-)- 3 equivs. 
88 
1 equiv. + 45 equivs. 
318 
1 equiv. + 6 equivs. 
128 
1 equiv. + 57 equivs. 
355 
1 equiv. + 9 equivs. 
153 
1 equiv. + 69 equivs. 
390 
1 equiv.+ 12 equivs. 
177 
1 equiv. + 81 equivs. 
418 
1 equiv.+ 15 equivs. 
198 
1 equiv. + 93 equivs. 
440 
1 equiv. + 20 equivs. 
223 
1 equiv. + 105 equivs. 
458 
1 equiv.+ 24 equivs. 
241 
1 equiv.+ 123 equivs. 
486 
1 equiv. + 30 equivs. 
263 
1 equiv. + 147 equivs. 
513 
1 equiv. +36 equivs. 
288 
1 equiv. + 195 equivs. 
538 
An experiment precisely analogous to the preceding was tried with the ferric chlo- 
ride in the place of the sulphate. The results were : — 
Ferric chloride. S^lphocyan. of 
potassium. 
Red salt 
produced. 
Ferric chloride. of 
potassium. 
Red salt 
produced. 
1 equiv. + 3 equivs. 
88 
1 equiv.+ 65‘4 equivs. 
338 
1 equiv. + 9 equivs. 
148 
1 equiv. + 83*4 equivs. 
370 
1 equiv. + ]5 equivs. 
190 
1 equiv. + 107'4 equivs. 
400 
1 equiv.+21 equivs. 
216 
1 equiv. + 131*4 equivs. 
428 
1 equiv.+ 28‘8 equivs. 
246 
1 equiv. + 155*4 equivs. 
456 
1 equiv. + 41 -4 equivs. 
286 
1 equiv. + 191*4 equivs. 
488 
1 equiv. + 5.3‘4 equivs. 
312 
1 equiv. + 239*4 equivs. 
528 
These two series of numbers give respectively the broken and the dotted lines in 
Plate VII. fig. 1. 
A glance at these curves will show that, although the actual amount of ferric sul- 
phocyanide produced from the same quantity of the sesquinitrate, chloride, or sul- 
phate of iron varies greatly, yet the increase of colour on the addition of more sulpho- 
cyanide of potassium maintains a somewhat similar ratio in each case. In Plate VIII. 
fig. 11 the commencement of the three curves is shown on an enlarged scale, and their 
close approximation becomes still more evident. The variations that do exist arise, 
2 D 2 
