295 
tensive forest fires still continue in Upper Michigan and Min- 
nesota.” 
,On the morning of Saturday, Oct. 7th, the report says; 
“The area of lowest pressure has advanced since Thursday 
afternoon from the lower lakes to the Kast Atlantic. Smoky 
and clear weather from Tennessee to Lake Ontario, and extend- 
ing southeastward. An area of remarkably dense smoke. 
exists at Washington, with fresh northwest winds,” 
Taking all these circumstances into account, I think that 
the conclusion is almost inevitable that the smoke at Wash- 
ington and Elmira had traveled from the region of the ex- 
tensive fires in Michigan; and the total distance passed over 
before. dissipation was at least 650 miles; and probably 
considerably more. 
This is greater than any distance I remember to have seen 
recorded. 
I have omitted mention of the prevailing winds west, of 
Elmira as I have not had the leisure to look up the reports. 
November 27th, 1871. 
Pror. B. N. Martin, Vice-President, in the chair 
T'wenty-one persons present. 
Dr. L. FEUCHTWANGER, presented a specimen of Infusorial 
Earth, said to come from Nevada, and reported to occur in 
immense quantities. The exact locality has not been, as yet, 
ascertained. It is quite white and much more friable than 
otherwise similar samples from that region. 
Pror. H. Wurtz said the exhibition of the present 
specimen gave him an opportunity of asking the chemists 
present whether they had observed that any of the Silica 
present in these Infusorial Earths was soluble, also whether, 
as was reported of this specimen, they contained Lime? 
