14' GEOLOGICAL MEMOIRS, 



10. If there should not hereafter be discovered other organic 

 bodies in the matter erupted from existing volcanoes, or should the 

 phaenomenon be rare, these isolated facts will have no general ap- 

 plication. Should such contents however be common in particular 

 kinds of erupted matter, and exist there in great abundance, we may- 

 hope to determine with some accuracy the probability or improba- 

 bility of subsequent mixture of these bodies in certain geological 

 formations. 



1 1 . It also seems that the present isolated case, since it offers an 

 inducement to careful investigation, ought not to be suppressed, but 

 rather made public, as marking the necessity of an earnest appeal 

 for collecting with great care many materials for similar inquiry. 

 The author wishes to take this opportunity of calling attention to 

 the subject, in order that in future advantage may be taken of every 

 instance in which it is possible to collect and forward different kinds 

 of meteoric and volcanic dust, carefully packing it in clean white 

 paper or in clean dry glass bottles. 



12. Lastly, the author disclaims all indirect conclusions that may 

 hence be drawn or attributed to him, especially with regard to the 

 depth beneath the earth's surface at which organic life may exist, and 

 reminds the reader that he is satisfied with the fact, of itself suffi- 

 ciently interesting, and that to follow it out step by step, although 

 it will be unquestionably an excellent and important work, must be 

 one in which it cannot be expected that we should attain any certain 

 result, except after a long series of investigations. 



2. Notes on additional specimens of Ashes from Hecla (Bericht, 

 1846, p. 149), ^th May, 1846. 



M. Ehrenberg states that a packet received by M. von Humboldt, 

 and containing ashes recently erupted from Hecla, has been put into 

 his hands to examine. A still more interesting relation is perceived 

 as the result of the investigation of the siliceous-shelled infusoria 

 and phytolitharia contained in this new acquisition, since out of 

 fifteen investigations, each upon about one-third cubic line of the 

 mass of ashes, as many as thirty-two distinct species of similar beings 

 have been recognized. Three of these are identical with species 

 from the Orkney dust. 



There have now been recognized thirty-seven or thirty-eight spe- 

 cies of organic bodies in volcanic bodies, obtained from the sub- 

 stances thrown out during the recent eruption of Hecla. Fifteen of 

 these had been before described as freshwater forms, occurring in 

 the turf of Hussavic in Iceland, and in the brackish water of Rei- 

 kiavik. Several others have been for some time known as occurring 

 in Labrador and Kotzebue's Inlet. Not one of the whole number is 

 decidedly new, and all of them are peculiar to fresh water. Hence 

 it appears that the sea can have nothing to do with the formation 

 of these ashes. 



It follows that it would be highly advantageous in future volcanic 

 eruptions, provided it is now too late for Hecla, if the following 

 queries could be solved : — 



