ENDLESS NATURE OF SCIENTIFIC RESEARCH. 27 



Xew knowledge is not like a cistern, soon emptied, but 

 is a fountain of almost unlimited power and duration. 

 The discovery of one truth leads to that of many 

 more. One new fact leads to a hundred researches, and 

 each research evolves a hundred new facts, and so on. 

 Not a single science, even of the mathematical ones, is 

 probably yet complete either in principles or details. 

 There is not a single force, nor even a single substance, 

 yet completely understood. The area of scientific dis- 

 covery enlarges rapidly as we advance ; every scientific 

 truth now known yields many questions yet to be an- 

 swered. To some of these questions it is possible to obtain 

 answers at the present time, others can only be decided 

 when other parts of science are more developed. All the 

 different branches of knowledge must advance together. 

 A geometric and mechanical basis of physical science can- 

 not be constructed until we know the forms, sizes, and 

 positions of the molecules of substances ; and as the whole 

 realm of attainable knowledge appears immensely great in 

 comparison with the powers of the human mind, the un- 

 folding of it will probably require an almost infinite 

 amount of labour, and therefore a vast period of time. 



During the prosecution of an original investigation, 

 the area of question and discovery enlarges as we proceed, 

 and the research in some cases develops into such com- 

 plexity and magnitude, that solution of its questions 

 appears for a time hopeless. Generally however, when 

 that discouraging point is attained, the subject begins to 

 clear, and by persistent research is gradually reduced to 

 order, and is found to conform to a few general laws or 

 principles. What is true in this respect of a single in- 

 vestigation has been largely found to be true of some of 

 the simpler sciences ; for instance, celestial mechanics ; 

 and will probably be also found to be equally true of the 



