336 PERSONAL PREPARATION FOR RESEARCH. 



thermo-electro-negative,paramagnetic, diamagnetic, noble, 

 base, earth, alkalinerearth, alkaline metals, &c. And by 

 further subdividing ( all metals ' into all the individual 

 metals, as many additional series of immediate inferences 

 might be drawn as there exist different metals ; and not 

 one of this very large number of inferences need be a mere 

 repetition. He therefore who admits the above original 

 statement must be prepared to admit all these (and many 

 more) inferences from it, and to deny their contradictories. 



If, in addition to this, we add to the original proposi- 

 tion any new truths, such for instance as by converting it 

 into the statement ' all metals and some f used-salts are 

 some heat-conductors,' we are thereby enabled to perform 

 many additional series of analyses and permutations of the 

 ideas, and draw many additional series of immediate in- 

 ferences. And from every one of the single inferences of 

 all these series, a contradictory idea which we know must 

 be false, might easily be formed, by converting each in- 

 ference into its negative statement. ' As the number of 

 possible terms which may be combined with the terms of 

 a premise is infinite, there may be drawn from any premise 

 an infinite number of inferences by combination.' 



In each of the instances here given, we analyse the pro- 

 position ; and by drawing an immediate inference we state 

 an additional truth, and at the same time detect and avoid 

 its contradictory error, and thus extend our knowledge. 

 Any statement in science, or any new truth obtained by 

 means of experiment or observation, might be treated in a 

 similar manner, and similar results obtained ; and it is pre- 

 cisely in this way, as well as by means of comparison and 

 generalisation, and also by means of indirect or immediate 

 inference, that new knowledge is, in the actual practice of 

 the art of discovery, extracted from the results of new ex- 

 periments, although we do not observe it at the time. 



