SCIENTIFIC MA TKHlA LISM. 401 



iugs and yearnings of the scientific intellect are directed 

 in vain. 



But here your tolerance will be needed. It was the 

 American Emerson, I think, who said that it is hardly 

 possible to state any truth strongly, without apparent 

 injustice to some other truth. Truth is often of a dual 

 character, taking the form of a magnet with two poles; 

 and many of the differences which agitate the thinking 

 part of mankind are to be traced to the exclusiveness with 

 which partisan reasoners dwell upon one half of the dual- 

 ity, in forgetfulness of the other. The proper course 

 appears to be to state both halves strongly, and allow each 

 its fair share in the formation of the resultant conviction. 

 But this waiting for the statement of the two sides of a 

 question implies patience. It implies a resolution to sup- 

 press indignation, if the statement of the one half should 

 clash with our convictions; and to repress equally undue 

 elation, if the half-statement should happen to chime in 

 with our views. It implies a determination to wait calmly 

 for the statement of the whole, before we pronounce 

 judgment in the form of either acquiescence or dissent. 



This premised, and I trust accepted, let us enter upon 

 our task. There have been writers who affirmed that the 

 pyramids of Egypt were natural productions; and in his 

 early youth Alexander von Humboldt wrote a learned essay 

 with the express object of refuting this notion. We now 

 regard the pyramids as the work of men's hands, aided 

 probably by machinery of which no record remains. We 

 picture to ourselves the swarming workers toiling at those 

 vast erections, lifting the inert stones, and, guided by the 

 volition, the skill, and possibly at times by the whip of the 

 architect, placing them in their proper positions. The 

 blocks, in this case, were moved and posited by a power 

 external to themselves, and the final form of the pyramid 

 expressed the thought of its human builder. 



Let us pass from this illustration of constructive power 

 to another of a different kind. When a solution of common 

 salt is slowly evaporated, the water which holds the salt in 

 solution disappears, but the salt itself remains behind. At 

 a certain stage of concentration the salt can no longer retain 

 the liquid form; its particles, or molecules, as they are 

 called, begin to deposit themselves as minute solids so 

 minute, indeed, as to defy all microscopic power. Asevap- 



