386 



Dr. P. F. Frankland. 



[June 18, 



Spongy Iron. — 5 grams of this substance were shaken up with 

 50 c.c. of urine-water in one case for one minute, and in another for 

 fifteen minutes ; in both cases the waters were subsequently allowed 

 to subside for half an hour before examination. The following results 

 were obtained : — 



Untreated water 609 centres per c.c. 



Treated ,, shaken for 1 minute. 28 ,, ,, 

 ,, ,, ,, 15 minutes 63 ,, „ 



Thus the reduction in the number of organisms by agitation is 

 exceedingly marked, and curiously the most favourable result was 

 obtained when the agitation was only continued for a single minute. 

 A pure cultivation was not obtained in the treated water, some colonies 

 producing liquefaction of gelatine, and others not, thus presenting a 

 contrast to the results obtained by nitration through this material. 



Chalk. — 1 gram of water was shaken up with 50 c.c. of urine- 

 water for fifteen minutes, and then allowed to subside for five hours. 

 The following results were obtained : — 



Untreated water . 8325 centres per c.c. 



Water after \h minutes' agitation with chalk 274 „ ,, 



A very large reduction indeed in the number of organisms was 

 thus obtained. 



Animal Charcoal. — 1 gram of animal charcoal was shaken up with 

 50 c.c. urine- water for fifteen minutes, and then allowed to subside 

 for nearly five hours. The following results were obtained : — 



Untreated water 8325 centres per c.c. 



Water after 15 minutes' agitation with 



animal charcoal 60 ,, „ 



The efficiency of the animal charcoal in this respect is thus very 

 markedly greater than that of chalk. 



Coke. — 1 gram of coke was shaken up with 50 c.c. of urine-water, 

 and then allowed to subside for forty-eight hours, as the water did not 

 clear before. The following results were obtained: — 



Untreated water Too numerous to be counted. 



Water after 15 minutes' agitation 

 with coke No organisms whatever. 



It thus appears that simple agitation with coke for fifteen minutes 

 is sufficient to entirely remove all organisms. 



China Clay. — 1 gram of this was shaken for fifteen minutes with 

 50 c.c. of urine-water ; subsidence was not complete for five days. On 

 examining the clear water it was found to yield a very large number 

 of organisms inaeed, thus showing that prolonged subsidence with 



