CAliADIA}i FISHERIES KXrKDiriON, 1911,-lo 



355 



nitrate solution is emptied into an ordinary smooth tumbler in which the measured 

 portion of the water-sample has been previously placed. Tlie fluid in the tumbler is 

 stirred by a glass rod to further the process, and the indicator is added when the chlor- 

 ine is nearly saturated. When nearing tlie saturation of the chlorine in the water the 



Fig. 7. — A s and.irdwatfT nit)e. 



silver nitrate solution is added in drops while stirring. The reading of the burette is 

 made at once while the red colour of the fluid lasts. The essential point in the titra- 

 tion is that all the different operations in one series of water-samples are done in 



