January 27, 1911] 



SCIENCE 



123 



is compelled to believe him. Harvey, how- 

 ever, does not provide information to facili- 

 tate repetition of his work — he offers little 

 aid towards the verification of his results. 

 Francesco Redi, the founder of experi- 

 mental biology, published his "Generation 

 of Insects" in 1660. His experiments 

 proved that insects are not spontaneously 

 generated in putrifying meat. His con- 

 clusion^ is sound, but he does not give 

 more than a general account of the actual 

 experiments. A century later Spallanzani 

 established the modern standard, and in his 

 works we find the details as to his evidence 

 put down with scrupulous care, for ex- 

 ample in his paper on the circulation 

 (1773) the single experiments are exactly 

 described. But Spallanzani in this, as in 

 other respects, was far in advance of his 

 time. 



In a cotemporary article we expect a 

 presentation of all the data necessary to 

 render subsequent verification by other ob- 

 servers possible. We further expect clear 

 information as to the amount of material 

 on which the observations were made, or 

 the number of experiments on which the 

 work is based. In other words, a modern 

 investigator will hardly receive considera- 

 tion for his researches unless he furnishes 

 every aid he can to facilitate criticizing 

 and testing his results. This severe stand- 

 ard has been only gradually evolved, but 

 is now stringently enforced in all depart- 

 ments of science and is the response ia our 

 practise to our need of eliminating the 

 purely personal factor. It would be ad- 

 vantageous if scientific authors generally 

 viewed the obligation of providing for 

 verification as an even more serious duty 

 than it is esteemed at present. It might, 



"At vero ubi loco ita clauao illud (stercorem 

 bovis) dentinui, ut intrare muscae & culices, et 

 ova sua ponere non possent, nihil omnino natum 

 vidi. 



indeed, be a wholesome practise to demand 

 that every scientific article should contain 

 a special section or paragraph on the 

 means of verif jdng the result, for verifica- 

 tion by Fachgenossen is second in impor- 

 tance only to discovery in the progress of 

 science. 



The conditions of scientific progress have . 

 changed greatly though very gradually. 

 Two hundred years ago the number of 

 active investigators was small. This year 

 there are at least ten thousand men of sub- 

 stantial ability carrying on original re- 

 searches, consequently each theme is being 

 worked at by several men, and the final 

 outcome is the consequence of collabora- 

 tion, which is none the less actual and ef- 

 fectual because it is unorganized, and is 

 usually not formally designated as collab- 

 oration. For example, our present knowl- 

 edge of the complex and very varied proc- 

 esses of cell-division has been constructed 

 not merely by successive accumulations, 

 but also by incessant debate and repeated 

 mutual criticism. If we examine a paper 

 on mitosis we find not merely the author's 

 own observations, but also references to 

 other related investigations, to specify 

 which there is often a formidable bibliog- 

 raphy. "Within a generation the modem 

 science of bacteriology has been created. 

 Within a few years radiology, the wonders 

 of which still thrill us, has suddenly come 

 into existence. Both great achievements 

 are the results of both the original observa- 

 tions and also the constant mutual discus- 

 sions of a number of scientific men. 



These conditions have rendered great 

 men somewhat less important than for- 

 merly. Science grows by the accretion of 

 ideas. Now, a great man has, let us say, 

 twelve new ideas, where a man of ability 

 has one. If science gets twelve new ideas 

 it matters little whether they come from 

 one man or from twelve. To a certain 



