400 NATURAL SCIENCE. June, 



observations, has individualised the science, characterised it, and 

 given it free development. The history of oceanography is an 

 example. 



Sniadecki in his remarkable work on the theory of dissolu- 

 tion (1808), said that " sciences are born or become perfect by the 

 discovery of their origins, i.e. of some observations embracing a whole 

 group of natural phenomena." And this is true, because if certain 

 sciences have had their founder, others have been called to life by 

 some special discovery, made in some earlier science. A simple 

 observation, well made, may be the germ of numerous discoveries 

 connected with a field of study absolutely unexplored. It may lead to 

 the explanation of phenomena hitherto inaccessible. Bacteriology is 

 a case in point. 



Thus then, although their origins are vague, sciences are born, 

 and each has a date of birth ; and if all sciences are not founded in the 

 same manner, if there are no general laws governing their mode of 

 origin as well as their development, we are yet able to affirm of all 

 that they never figure in history except after one more or less definite 

 date which can be determined. There are young sciences and old 

 sciences ; some are still in embryo (still incorporate with the mother 

 science and developing through her) ; others have died, but their ruins 

 still serve and will serve always. Sciences, then, are born. And this 

 fact alone gives to each a definite relationship, which may be dis- 

 covered by the study of its history. 



A general and philosophical history of sciences, such as is yet 

 unwritten, would therefore be of the highest utility. Houzeau, in one 

 of his admirable addresses to the Academy of Belgium, has shown 

 that the history of science reveals to us a regular evolution of the 

 human mind. For sciences have evolved like everything else. But 

 more than that. Sciences live ; live in humanity just as languages do, 

 or as beings live in nature. The sciences, in the same way as 

 languages, have a genealogical tree. They also are differentiated. 

 The history of the development of science is like that of life, and 

 results in a tree with branches and twigs, of which each twig represents 

 one science. The branches are the mother sciences. The historian 

 of science should begin his work by the study of this tree ; and only 

 when it has been traced and explained thoroughly, shall we be able to 

 say we have a history of science. 



Order therefore exists — natural order. Natural order is the 

 genealogical tree.' Classification therefore must be preceded by a 



iln his introduction to the Encyclopaedia (17S1) d'Alembert after having 

 characterised the different sciences, adds " Apres le detail ou nous sommes entres 

 sur les differentes parties de nos connaissances, et sur les caracteres qui les dis- 

 tinguent, il ne nous reste plus qu' a former un arbre f^htealogique ou encyclopediqiie qui 

 les russemhle sous un mcme point de vue, et qui serve a marquey leur origine et les liaisons 



qu' elks out entre elks Quoique 1' histoire philosophique que nous venonsdedonner 



de r origine de nos idees, soit fort utile pour faciliter un pareil travail, il ne faut pas 

 croire que 1' Arbre encyclopedique doive ni puisse meme etre servilement assujetti a 



