THE SALT-WATER FISHERIES OF BOHUSLAN. 147 



As regards literature we must have reference not only to that more 

 scientific portion of it contained in book form, but also to that more 

 scattered information found in newspapers and periodicals'* or in the 

 various official documents in city or state archives. In order to make 

 full use of this source of information so very important for the herring- 

 fisheries, it is of course necessary to consult the more important foreign 

 works and documents (for example, the Danish, Dutch, and British). 

 The importance of studying the special literature of a subject will be self- 

 evident if we remember the well-known fact tiiat in those fields of human 

 knowledge which have been cultivated most, no one, whatever his natural 

 talents may be, can, through his own exclusive endeavors, obtain that 

 knowledge which is stored up in literature for the benefit of posterity, 

 much less carry his knowledge very far beyond this limit. A thorough 

 acquaintance with all the facts which others have brought to light on a 

 certain subject must form the starting-point for those endeavors from 

 which the greatest possible results may be expected. 



But it is not only that knowledge which is stored up in literature 

 which must be taken into consideration, biTt everything which has been 

 collected, preserved by tradition by the fishermen and the superintend- 

 ents of the fisheries. The gathering and working up of this very hete- 

 rogeneous material is connected with considerable difficulty, and presup- 

 poses a good deal of experience obtained by direct personal observations, 

 as well as a varied knowledge of all the literature on the subject. The 

 great mass of the people are often more inclined to be influenced and even 

 prejudiced by anything coming from foreign parts ; the experience of 

 foreign countries is doubtless also in many respects richer and more 

 varied than our own and more fully corroborated by experiments and 

 scientific investigations. The chance of increasing our stock of knowl- 

 edge by studying the experience of foreign countries should, therefore, 

 not be neglected. In doing this, however, it should be remembered that 

 there are great differences of nature, law, and economy between our 

 own and other countries, which point is but too frequently lost sight of. 



The material obtained from literature and the experience of fishermen 

 must be critically sifted, and for this purpose as well as for extending 

 our knowledge beyond this limit, direct personal observations and exper- 

 iments are necessr.ry. Experiments are moreover required to prove the 

 correctness of opinions that have been advanced, and of hypothetical 

 explanations, 



A full description of the best means for utilizing these various sources 

 of knowledge will be given below when each jwrtion of the fishery 

 investigations will be treated separately. 



§ 11. Fishing is a trade which absolutely requires special experience. 

 This experience embraces the proper use of the different fishing-appa- 



■■See A. Boecl; in "Xordisk Tichskrift for Fiskeri/' VII. Copenhagen, 1872, p. 7. 



A. V. Ljioxjman, " rrciimiiuir i>'«-a;/eZse"— Preliminary report for 1873-1874, on the 

 investigations regarding the herrings and herring-fisheries on the western coast of 

 Sweden. Upsahi, 1874, p. 70. 



