370 



Prof. Carnelley and Mr. T. Wilson. [Feb. 16, 



The weather had been fine and dry for a long time previous to 

 August 9th, but between that and the 15th there were several days 

 of rain. 



It will thus be seen that not a single sample contained bacteria, and 

 that all the micro-organisms obtained consisted of moulds, amounting on 

 the average to 3'5 per litre. 



Now Miquel and Dr. P. Frankland have each shown that the air is 

 much richer in micro-organisms during the summer than during the 

 winter, there being a minimum about midwinter and a maximum 

 about July and August, thus : — 





Miquel. 



P. Frankland. 



Montsouris. 



Paris. 



South 

 Kensington. 



Winter (Dec, Jan., Feb.) 



2 





21 3 



12 



Spring (March, April, May) . . 



5-0 





47 '9 



29 



Summer (J une, July, Aug.) . . 



6-4 





50-5 



74 



Autumn (Sept., Oct., JSTov.) . . 



4-8 





37-0 



30 



It hence follows that the number of moulds we found in moorland 

 air was probably a maximum, since the determinations were made in 

 August, and that bacteria are absent all the year round in pure air 

 from moors and hills away from towns. 



In order to give an idea of the number of micro-organisms in 

 moorland air as compared with air from other localities, the following 

 table is appended, more especially as many of these data are not 

 generally accessible to chemists : — 



