FROM THE AIR OF MANCHESTER. 271 



bottle^ and on the 13th of this month Dr. Smith requested 

 me to examine the matter contained in this water. An 

 illness prevented me from giving it so much attention as I 

 could have wished. 



The water containing this air-washing was first ex- 

 amined with a power of 50 diameters only_, for the purpose 

 of getting a general knowledge of its contents ; afterwards 

 maguifying-powers varying from 120 to 1600 diameters 

 were employed. 



During the first observations^ few living organisms were 

 noticed ; but^ as it afterwards proved, the germs of plant 

 and animal life in a dormant condition were present. 



I will now endeavour to describe the objects found in 

 this matter, and begin in the order in which they appeared 

 most abundant. 



1st. Fungoid Matter. — Spores or sporidia appeared in 

 numbers ; and, to ascertain as nearly as possible the nume- 

 rical proportion of these minute bodies in a single drop of 

 the fluid, the contents of the bottle were well shaken, and 

 then one drop was taken up with a pipette ; this was spread 

 out by compression to a circle | an inch in diameter. A 

 magnifying-power was then employed which gave a field 

 of view of an area exactly looth of an inch in diameter, 

 and it was found that more than 100 spores were contained 

 in this space ; consequently the average number of spores 

 in a single drop would be 250,000. These spores varied 

 from the io,oooth to the 50,000th of an inch in diameter. 

 The peculiar molecular motion in the spores was observable 

 for a short time, until they settled on to the bottom of the 

 glass plate; they then became motionless. 



The mycelia of these minute fungi were similar to that 

 of rust or mildew (as it is commonly named), such as is 

 found on straw or decaying vegetation. 



When the bottle had remained for 36 hours in a room at 

 a temperature of 60°, the quantity of fungi had visibly in- 



