> 



ll 



crate 



^■^ %" 



numbers f 



'''^^•tho 



K 



) 



I 



contai._ : 



ns a 



r 



addition^ the 





•^5 \vho says>;.r 



''^" deposited Id f, 

 ', c^"cctcd on pi*; 



and have found :;. 

 ; of animal and v£;;L 



^ ia the greatest^: 



some closely K 



ims 



> 



««^c- and with tk 



n ■ 



rr 



;red to be tk e 



Is, though we ««■ 



^u^-« of any 



:l: 



1 r* 



'ns 



of starch i» : 



) 



the p 



resence 



off' 



ero.e?^; 





i*t 



.i'^- 



^ 



if c** ^ » 



THE BEGINNINGS OF II FE. 



283 



Poucbet was the first to call attention. When com- 

 pared with the whole quantity of dust examined, or 

 even with the whole quantity of organic matter, both 

 ecras and spores may be said to be of rare occurrence. 

 We have not in any instance detected dried animal- 

 cules, which were resuscitated by moisture ; and when 

 the dust has been macerated by water, none have ap- 

 peared until several days afterv/ards, until after a lapse 

 of time when they would ordinarily appear in any or- 

 ganic solution.' The testimony of Dr. Maddox is also 

 very much to the same effect— as to the comparative 

 paucity of recognizable living germs, even when large 



quantities of air are 



contents on a limited area of glass, covered 



viscous material^. 



made to deposit their floating 



a 



It will be perceived, therefore, that in all these at- 

 tempts to ascertain the nature of the solid particles in 

 the atmosphere, even large quantities of air constantly 

 renewed serve only to yield evidence of the most 

 sparing distribution of spores or ova. But, if we limit 

 ourselves to the employment of means which are more 

 exactly comparable with the atmospheric conditions to 

 which our infusions are exposed, we discover a far 

 greater paucity of reproductive particles. If we place 



1 'Monthly Microsc. Journal,' June, 1870, p. 290. Other contributions 

 have been made to our knowledge of this subject which are too numerous 

 to mention. We may, however, cite valuable papers by Dr. Sigerson 

 and Dr. Arthur Ransome, which are to be found in the same volume of 

 the * Monthly Microsc. JoxirnaL' 



