82 Werner's Advice to Students of Geology. 



men desirous of instruction. When, on traversing a country, 

 they have acquired a general idea of its nature, and wish to go 

 farther, it is with difficulty that they can persuade themselves to 

 retrace their steps, to see and see over again the same object un- 

 der all its aspects, and in all its details ; and yet these are the ob- 

 servations that are truly useful to science, those which assure its 

 progress, and which it carefully preserves in its archives. Let 

 the geologist who would make such observations, undertake, for 

 example, the complete description of a country, interesting from 

 its mineralogical nature, but of small extent. Let him acquire 

 a first idea of the ground, by traversing it in two or three dif- 

 ferent directions, so that he may be enabled to form a right 

 plan of the labour to be executed, and determine the series of 

 questions to be solved. Let him again return to the places. 

 His intelligence, and the habit of observing, will point out to 

 him, whether, from what he has already seen of the country, or 

 from what he will see by multiplying his researches, what are the 

 points whither he ought to betake himself to make his observa- 

 tions, and acquire his data for the solution of the questions 

 which he has proposed to himself. He will not leave the ground 

 until he has solved them, or until he has been convinced of the 

 impossibility of solving them in whole or in part. 



It may be considered as superfluous to recommend to the ob- 

 server to see and note the facts such as they really are, divesting 

 himself of all prejudice, and of all desire to make them enter in- 

 to a systematic theory. A system is frequently nothing but a 

 coloured-glass, which, placed before the eyes of the naturalist, 

 alters or even changes the colour of the objects seen through it. 

 Although we recommend the rejection of all theory not suf- 

 ficiently founded on facts, and maintain that actual observa- 

 tion is the only true basis of geology, we would notwithstanding 

 recommend to him who devotes himself to its study, not to con- 

 fine himself to the determination and collection of facts. It is 

 also necessary, as we have already remarked, that he class them, 

 in order to understand their relations, and acquire a general 

 knowledge of their nature. He must combine them, in order to 

 draw inferences from them. It is even necessary that he should 

 endeavour to ascend to a knowledge of their causes ; but, in his 

 investigations, he ought always to bear in mind, that all the 



