1888.] Number of Micro-organisms in Moorland Air. 369 



III. i 'Note on the Number of Micro-organisms in Moorland 

 Air." By Professor Carnelley/, D.Sc, and Thos. Wilson, 

 University College, Dundee. Communicated by Sir Henry 

 Roscoe, F.R.S. Received February 3, 1888. 



As no determinations appear to have been made of the number of 

 micro-organisms in moorland air, the following results obtained last 

 summer may be of interest as forming a small contribution to our 

 knowledge of the distribution of micro-organisms in the air of 

 different localities. 



Our determinations were made " on the heather " in the neigh- 

 bourhood of Midtown, in the parish of Tanadice, in Forfarshire. 

 This forms a part of the Clova district, so well known to botanists as 

 the habitat of many rare mountain and moorland plants. Midtown 

 is situated at a height of about 1000 feet above the level of the sea, 

 and is far removed from towns and other sources of contamination, 

 as is evidenced by the fact that the nearest railway is about six miles 

 away. 



We also made simultaneous estimations of the carbonic acid by 

 Pettenkofer's method. The process employed for the determination 

 of the micro-organisms was the " flask method," which we have 

 already described in a previous paper. The samples of air were 

 taken at a height of about 3 feet from the ground. The results 

 obtained are represented in the following table. 10 litres of air were 

 aspirated in each case. More determinations would have been made, 

 but owing to an accident the remainder of the flasks were unfor- 

 tunately spoilt. 



Date. 



1887. 

 Aug. 3rd 



5th 



8th 

 9th 

 15th 



Time. 



5 p.m. .. 



9.30 a.m. 



9.20 a.m. 

 2 p.m. .. 

 10 a m. .. 



9.30 a.m. 



Weather. 



Wind. 



Temper- 

 ature. 



Bright sunshine, no 



clouds 

 Bright sunshine, 



cloudy 

 Cloudy 



Moderate, S.E. 



Strong, S. 



Gale, W 



Strong, W 



Bright sunshine, few Gentle, \V 



clouds 



Cloudy j Moderate, N.W. 



Micro- 

 organisms 

 per 10 litres 

 of air. 



4-2 



4-0 



4-0 

 3*3 



3- 6 



4- 3 



