440 



Journal of Agriculture. 



[i I July. iqto. 



In choosing between alum and chloride of iron, the price is at first 

 sight in favour of the former. Weight for weight, however, i lb. of 

 chloride of iron is worth 2 lb. of alum, and this fact, together with its 

 easy solubility, turns the scale in its favour. 



The " brilliancy " of the action of iron chloride, that is, the efficiency 

 with which it acts, the rapidity with w^hich it causes the mud to settle, 

 and the ease with which it can be handled owing to its solubility, make it 

 ideal, and it is most desirable that it should be on the Australian market 

 at as cheap a rate as possible. In Germany, it is advertised at about 

 2|d. per lb., and this price doubled would still leave it a cheap chemical 

 for clearing water. 



Chloride of iron is not merely harmless. It is more, it is a most 

 valuable mineral constituent for all animals. There is consequently a 

 distinct gain, even if too msuch is added to the water. 



As previously mentioned, however, the added chemical (if not in^ 

 larger quantity than required) is thrown out with the mud. 



Experiments on a Practical Scale with Chloride of Iron. 



These consist of the clearing of large volumes of water (a) in \xon 



tanks, (b) in the open field. 



TanJi Experiments. — A large cylindrical tank fitted as in the accorn 



panving diagram was kindly supplied by Messrs. Felton, Grimwade, and 



Co., of Melbourne. It is 

 suggested, however, as the 

 result of experience gained 

 with this one, that the elbow 

 piece inside is not necessary. 

 For a tank, which it was in- 

 tended to use continuously, a 

 wide outlet, with tap in the- 

 centre of the floor, would V)e 

 useful for flushing out de- 

 posited mud. 



The dimensions of the- 

 tank were — height 7 feet, 

 diameter 5 feet. Calculated 

 total capacity, 850 gallons. 



At 2 p.m. (20th April) a 

 I lb. bottle of chloride of 

 iron was opened and filled 

 with water up to the neck. 

 All the solid dissolved in this 



Syphon For 'Sr 



?//»/? /7 wafer ^f 



clean water. 



w 



^^ 



7.' 



Mud 



;-, j Suggested outlet Tor 

 removing mud 



cylindrical tank. 



volume of water, and at 4.30 p.m. half the bottle was emptied into the 

 tank which contained 600 gallons of muddy pond water. The water 

 was stirred njund with a short stick for half-a-minute in order to 

 uniformly distribute the iron chloride solution. 



Next morning, at 9 o'clock, water was drawn off from the bottom 

 of the tank by the tap and syphon. It proved perfectly clear and clean,, 

 and the photograph on page 441 shows it contained in a large bottle 

 10 inches in diameter and standing between a like bottle containing Yan 

 Yean (at its" t)est), and another containing the muddy water as it was- 

 prior to treatment. Thus, overnight, 600 gallons of dirty muddy water 

 not fit for drinking, for use in the dairy, or the holise, were converted. 



