314 Report on a Manuscript Work of M. Andri. 



pected that it would be necessary to be able to answer them 

 before attempting to make a system. 



Hence the reason why some will have millions of years 

 for the formation of secondary mountains, while others 

 pretend that about 5000 years ago they were formed in one? 

 All the intermediate parts between these two extremes have 

 had their defenders. 



There already exist ten or twelve hypotheses for the par- 

 tial explanation of the formation or' the basin of Paris, yet 

 not one of those who have formed them knows what exists 

 in one small corner of this basin, which contains only a few 

 square toises. At Grignon there are 600 species of unknown 

 shells, besides 40 or 50 that are supposed to be known. 

 This fact is stated by M. de Lamarpk, after several years re- 

 searches. Neither does one of them know that our gypsum 

 contains the bones of 12 or 15 quadrupeds, which neither 

 resemble those seen here or elsewhere ; another fact which 

 has only been ascertained after ten years labour. 



Judge then what ought to be the explanations coolly ima- 

 gined in the closet by persons to whom these two little 

 circumstances of the phaenomenon were unknown. How 

 then ought a learned society to act, in order to extend and 

 improve so interesting and useful a science, and direct it to 

 real and attainable objects ? It ought in this, as in every 

 other science, to encourage by its approbation all those who 

 state positive facts, and preserve the most rigid silence on 

 the systyems which succeed them. In this manner the au- 

 thors of systems treat the observers or collectors of facts. It 

 is curious to see them all, the moment any discoveries are 

 made by observers, ready to seize them, arrange them ac- 

 cording to their own ideas, and convert them into weapons 

 against their adversaries. It appears as if anatomists, zo- 

 ologists, and mineralogists, were but workmen destined to 

 furnish materials for their fantastical fabrics. 



Happily for the example of those who may be tempted to 

 jwrsue such a course, these castles in the air vanish like ap- 

 paritions, and the more solid edifice raised on facts and in- 

 duction begins to appear. The plan, if we may so speak, 

 is already traced; men of judgement at the end of the 18th 



century 



