On the Distribution of Micro-organisms in Air. 281 



(V 



o 



oS 

 Eh 



'Number of 

 micro-organisms 

 falling on 

 1 horizontal 

 square foot 

 per minute. 



00 

 00 



CO 







1> 



rH 



157 



vO 

 rH 







3 "(3 ' — •> 

 O O, t3 













Numbe: 

 colonies ; 

 10 litres < 

 (calculal 



o 



00 





rH 



OS 



Number of 

 colonies 

 obtained from 

 given volume 

 of air. 



39 in 20 lits. 

 18 moulds. 



15 in 20 lits. 

 9 moulds. 



8 in 11 lits. 

 7 moulds. 



21 in 12 lits. 

 8 moulds. 



29 in 10 lits. 

 8 moulds. 



ment. 



her variable in strength 

 ous rain. Sunshine, 



Wind S.W. by W., gentle, but variable in strength and direc- 

 tion. Roads and pavement still wet from rain on previous 

 night. 12-5° C. 



Wind E., moderately strong, but variable in strength and 

 direction. Roads, &c, wet with dew. 8 6° C. 



wet, pavement dry. 



Wind W. by N.W., very gentle, but occasional gusts, j 

 Everything dry with hard frost. 0*8° C. 



Conditions of experi 



Wind W. by N.W., moderate, but rati 

 and direction. Four days' ^revi 

 roads wet, pavement dry. 6*9 C. 



Wind S.W., very strong. Roads 

 9-7° C. 



Date. 1886. 



November 13th. 



11 A.M.— 12.30 P.M. 



November 20th. j 



11 A.M. 



November 26th. 

 2.45—3.35 p.m. 



November 29th. 

 2.45 P.M. 



December 3rd. 



3 P.M. 



