XIV . 



a mining company in Copenhagen established a regular produc- 

 tion of cryolite at lvigtut in order to use this mineral for the 

 manufacturing of soda after the method invented by Professor 

 J.J.Thomsen in 1852. By this mining enterprise, which is kept 

 going to this day, a rich source of new experiences were 

 opened to the mineralogical science ; the mineral occurrence 

 at lvigtut with its numerous fluorides has proved to be one of 

 the most interesting and peculiar localities known. 



From all the mineralogical exploring expeditions hitherto 

 mentioned the collected minerals, or, at all events, the greater 

 part of them, were delivered to the museums of Copenhagen. 

 Towards the year 1870, however, the interest in arctic exploring 

 expeditions increased very much everywhere in the scientific 

 world, and from this time journeys to Greenland were also made 

 from foreign countries, which journeys have contributed essen- 

 tially to the knowledge of the topographical mineralogy of this 

 country. All the principal results of the foreign expeditions 

 have been published, but it may, of course, be possible that a 

 few further contributions of topographical-mineralogical interest 

 wilh regard to Greenland may still be found in the foreign 

 museums. For practical reasons, however, it has been necessary 

 not to make use of museums outside of Copenhagen by the 

 preparation of the hand-book; this restriction has caused so 

 much the less hesitation as there was no reason to suppose 

 that it would be of any considerable influence. The fact is that 

 after 1870 also the number of Danish exploring expeditions, the 

 collected minerals of which are kept in our museum, has in- 

 creased very much, and these expeditions have carried through 

 a systematic and thorough exploration of the country. Only in 

 the northernmost and north-eastern parts of the island, regions 

 are found that have not yet been visited by Danish expeditions; 

 but as the collections which have been carried home by foreign 

 expeditions from these regions so difficult of access, have been 

 examined and described abroad with special fulness, they have 



