204 Dr. A. Carpenter on 



proof of the value of the preservative fluid, he exhibited the 

 mucous-Hke ova mass of an Eolis, which was in quite its 

 natural condition, although eight years of age as a micro slide. 



The cement used by Mr. Lovett for fixing cells for this fluid, 

 for fixing the cover glasses to the cell wall, or for covering 

 sunk cells, is composed of equal parts of red lead, white lead, 

 and brown litharge, pounded to a powder and kept dry. When 

 wanted for use, a little is mixed with japanuer's gold size as 

 thick as required, and it must be used with great care to ensure 

 success, but in this case also the lecturer stated that practice was 

 the best way to satisfactory results. 



75. — MicROBic Life in Sewer Air. 



By Alfred Carpenter, M.D., J. P. 



(Bead April 10th, 1889.) 



The peripatetic world is now and then convulsed by agitations 

 against the smells which come from openings into sewers. " Shut 

 them up," say the most energetic and demonstrative. Some- 

 times this is effected, sometimes it is not. In the heated discus- 

 sions which spring up, in consequence of some stinking outlet, 

 argument is useless. The loudest exclaimers often gain the day 

 rather by the loudness of their declamation than by the correct- 

 ness of their reasons. 



I propose to consider the question in its bearing upon the 

 public health in a scientific rather than in a partisan spirit. 



The reasons for objecting to smells from sewers are sound 

 enough. It has been proved conclusively that sewer smells do 

 promote sickness. It is reasonable, therefore, that those who 

 object to pay an unnecessary doctor's bill, and at the same time 

 incur the risk of losing one of their beloved ones, should be loud 

 in their antagonism to smells from ventilating gratings. 



The first point to be determined is the actual nature of the 

 smells, and, secondly, the causes which produce them. There 

 are various kinds of smells, some pleasant, others objectionable, 

 and some decidedly obnoxious, and one class is utterly offensive. 

 This division is not satisfactory, because some smells which are 

 grateful to some persons are most offensive to others. We 

 cannot divide them in this way. Another classification might be 

 made according to their manufacture. The odour of flowers and 

 of individuals — human or animal — differ as to their causation 

 from the odour of a gas works, and yet they are allied. These 

 smells arise from chemical changes in the structures of the 

 bodies engaged, which give off minute particles of matter, 



