196 Air and Water Poisoning 



" No ammonia, nitrates or sulphuretted hydrogen were- 

 found. 



" The suspended organic matter, as shown on microscopic- 

 examination, consisted entirely of those plants and animals 

 which live in pure water only, viz. : — 



" Monads. 



" Eotifers. 



" Desmids — Micrasterias, furcata and pinnatifida, Stancas- 

 trum, gracile, paradoxum, and orbiculare, Arthrodesmus 

 incus, docidium (?) truncatum. 



" There were no''fungi or confervse of any kind, and the 

 absence of all animalcules of the kolpod group was also- 

 marked." 



See Plate I., opposite page. 



I have on other occasions found other organisms ; but the 

 general observation as to their character has always held 

 good. 



The recent report of the City health-officer, and the com- 

 ments of Dr. Richardson, have made this analysis important 

 evidence in a direction not before contemplated. Nearly 

 three months since, Mr. Girdlestone, having a suspicion 

 that there was at least a risk of the Van Yean reservoir 

 receiving the drainage from Whittlesea township, even if it 

 had not already done so, determined on investigating the 

 matter himself, and invited Dr. Richardson and myself to 

 accompany him, and to assist in the inspection. At first I 

 hesitated to make any deliverance on the subject, from a 

 motive of delicacy, considering it as his case, and even when 

 Dr. Richardson's paper appeared,. I determined to let them 

 enjoy all the kvSos ; but now that they have been stigmatized 

 as alarmists, and the proceeding treated in some quarters 

 with mixed slight and derision, I think it only fair to take 

 my share of the responsibility, especially as I may be able 



. to throw a little light on the matter from a direction not 

 hitherto considered. 



I examined the water while investigating the subject of 



. sewage, &c., in order to satisfy myself and the Health 

 Committee that the noxious matters detected in the other 

 cases cited proceeded entirely from the suspected sources. 

 With my own knowledge of the Yan Yean water, which I 

 have so repeatedly had occasion to analyse I regarded this 

 examination as little more than a necessary formality, but I 

 am now very glad that I made it. , My friend Mr. Johnson 

 has lately published an analysis of the water, which agrees 



