EXAMPLES OF THE EXPLANATION OF LAWS. 571 



This example displays the second mode of resolving 

 complex laws, by the interpolation of intermediate 

 links in the chain of causation ; and some of the steps 

 of the deduction exhibit cases of the first mode, that 

 which infers the joint effect of two or more causes 

 from their separate effects ; but to trace out in detail 

 these exemplifications may be left to the intelligence 

 of the reader. The third mode is not employed in 

 this example, since the simpler laws into which those 

 of respiration are resolved (the laws of the chemical 

 action of the oxides of iron) were already known laws, 

 and did not acquire any additional generality from 

 their employment in the present case. 



3. The property which salt possesses of pre- 

 serving animal substances from putrefaction is re- 

 solved by Liebig into two more general laws, the 

 strong attraction of salt for water, and the necessity 

 of the presence of water as a condition of putrefaction. 

 The intermediate phenomenon which is interpolated 

 between the remote cause and the effect, can here be 

 not merely inferred but seen ; for it is a familiar fact, 

 that flesh upon which salt has been thrown is speedily 

 found swimming in brine. 



The second of the two factors (as they may be 

 termed) into which the preceding law has been 

 resolved, the necessity of water to putrefaction, itself 

 affords an additional example of the Resolution of 

 Laws. The law itself is proved by the Method of 



peroxide in the lungs. If the carbonate, then the beneficial effect, 

 on the animal economy, of drinks which give an artificial supply of 

 carbonic acid to the system, would be, to that extent, deductively 

 demonstrated. 



