i 3 4 THE POPULAR SCIENCE MONTHLY 



or universities : that these discoveries on British soil, like those involved 

 in the theories of Newton, Harvey and Young, were taken up in Paris 

 by members of the Academy of Sciences and through the aid of the 

 government and by means of a wise organization of students of science 

 were tested and their value made known to the world. It is to LaPlace 

 of the Paris Academy of Sciences, more than to any one else, that New- 

 ton's theories were made known and were at last universally accepted. 

 Paris up to the middle of the nineteenth century was the most impor- 

 tant center of organized scientific study in the world. It was here that 

 the experiments of Lavoisier in chemistry were made, here that Cuvier, 

 Arago and scores of other men introduced into their studies the 

 methods of exact measurements and weights, brought scientific pro- 

 cedure to mathematical precision and stated results in mathematical 

 formulas. It was in Germany, in the universities rather than in the 

 academies, that these results were recorded, and through numerous 

 periodicals given to the world. Germany long has been, and still is, the 

 country of year books in which the history and progress of each special 

 science is carefully traced and preserved for the benefit of the scholar. 

 In France pains were taken with the literary form in which scientific 

 discoveries were published, and a popularity was thereby secured for 

 them unknown either in England or in Germany. 



Two factors enter into intellectual progress, the extension or increase 

 of knowledge, and its condensation. Eeports of discoveries in any de- 

 partment of learning must be reduced to their lowest terms, or they will 

 not be read, much less studied and made of use. In its accumulations 

 of knowledge the nineteenth century is unsurpassed, but in condensa- 

 tion of knowledge some think it inferior to the time of Pericles in 

 Athens. Nor is it certain, others say, that during the Kenaissance, Italy 

 did not surpass anything done in our modern era, and many give the 

 palm to Prance during the sixteenth and seventeenth centuries. But 

 the nineteenth century has no rival in its success in discovering and 

 marking out new and better methods than any previously known, for 

 increasing knowledge. It was in that century that the important con- 

 ception of the unity of knowledge became prominent. In the opening 

 of the twentieth century the desire to discover truth has not lost in 

 strength, but our students and thinkers are exceedingly careful in the 

 examination of the criteria of truth, for they have learned that not all 

 which seems true, or is proclaimed as true, is true and can be accepted 

 as true. Still men of science are wont to speak of their methods of 

 study as " exact," and to call their discoveries " exact truth." The 

 truths involved in these discoveries are tested by being brought into con- 

 tact with practical life, that is, tested by experience. In all this 

 thought is present and prominent. It is the thinker in the laboratory, 

 in the factory, in the new industry established as the outcome of years 



