10 PROCEEDINGS OF THE 



Sundry photographs, specimens of skin and some animal organ- 

 isms, dredged from the harbor of Newport, R. I., received from Mr. 

 Powell for distribution among the members, was presented. 



November 7th, 1870. 



Vice-Director, Wm Pepper, M.D., in the Chair. 



Nine members present. 



Dr. J. G. Hunt presented the following report in regard to the 

 dust shower, which was accepted, the Committee discharged, and 

 the Corresponding Secretary requested to forward the same to the 

 authorities at the Smithsonian Institution. 



The Committee to whom the dust, sent by H. A. Cutting, and said to hare 

 fallen from the air in Vermont Feb. 12, 1870 ; was referred for examination, 

 make the following report : 

 The dust effervesced under the action of an acid. 



On microscopical examination we find as follows : 



1st. Much granular amorphous matter. 



2d. Many round or oval granules, perfectly transparent. These disappear 

 when treated with nitric acid. It is probable that silica forms no part of 

 their composition. 



3d. Spores of fungi or gonidia of some lichen. 



4th. Diatoms. 



5th. Fragments of vegetable cells, too imperfect for identification. 



6th. Cells of coniferous wood the genus Pinus having the peculiar de- 

 posit characteristic of these cells absent in spots. 



7th. Other cells of coniferous wood with smaller markings than those of the 

 pine ; five dots in a row and two parallel rows in each cell, and the cells ter- 

 minating transversely and not obliquety as in the pine. 



8th. Many cells of an Alga, resembling red snow, or Protococus nivalis, or 

 Palmella cruenta, or Porphrydium, as the unfortunate plant is now called. 

 These cells were in the stage of binary subdivision, well known in that Alga. 



We see no reason to doubt that this dust is the ashes of someburning for- 

 est, which has been sifting the higher regions of the atmosphere with its mi- 

 croscopical fingers, gathering in its transit some recognized organisms and 

 many we could not identify. The distance it may have travelled we cannot 

 measure, nor is it important. 



To the action of the winds Linnaeus ascribes the importation into Europe 

 of the Conyza aerulca of Canada, which now infests the north of France. 



Certain lichens from the mountains of Asia, taken up by whirlwinds, 

 travel among the clouds and, imbibing watery vapor upon the journey, grow 

 during their peregrinations, until they fall at vast distances from where they 

 started. " This rain of plants sometimes forms on those places a layer five 

 or six inches deep. Men feed upon them, and what they cannot consume is 

 given to the cattle." We have been told by aeronauts that they have seen 

 thistle seeds floating above the clouds. If those heavier bodies have been 

 carried vast distances, it is not improbable that this fine dust may have fol- 

 lowed a devious and far distant path. 



Your Committee would request Mr. Cutting to send to this Section a copy 

 of his paper on Dust Storms, when completed. 



All of which is respectfully submitted. 



(Signed) Dk. J. G. Hunt, 



Dk. Wm. B. Corbit. 



