THE PREPARATION AND USE OF LIME AS A NEUTRALIZER 193 



instead of the user. As is shown below, it takes 74 pounds of 

 completely hydrated lime to equal 56 pounds of quicklime for 

 neutralizing purposes. Of course, the hydra tion is often only 

 partial and then the difference is not so great. 



It is really a lime mixture in the form of milk of lime, and not 

 limewater, that is used, as lime is only soluble to a very small 

 extent in water, and it would require too much of this to make its 

 use practicable. 



Lime should be free of such impurities as sand, clay and iron, 

 and the lime preparations offered by responsible firms for neu- 

 tralizing purposes usually are. 



It is very important that the lime mixture be properly pre- 

 pared. Much more trouble arises from improper preparation 

 than from defects in the lime itself. 



Quicklime is obtainable in powder form, packed in tin canis- 

 ters. This form gives excellent satisfaction, as the quicklime is 

 clean, uniform and free of waste material, and keeps until it is 

 all used; whereas in lump lime there is considerable waste, 

 through air slaking and the rejection of unsuitable lumps. 



A very suitable mixture is made up in the proportion of 17 

 pounds of water to 3 pounds of quick lime. The water ^should be 

 as near boiling as possible and the lime should be added to the water 

 and not the water to the lime. The lime should be added in four 

 installments instead of all at once, and the mixture stirred thor- 

 oughly after each addition of lime. If properly prepared the 

 mixture will be very smooth and free of visible lime particles. 

 When cool, it may be tested by putting the hand or a smooth 

 butter spade into it and withdrawing. If smooth, showing no 

 lime particles, it is a good mixture; if it shows a very few par- 

 ticles, it is fair; and if it shows many particles it is a poor mixture 

 and is more likely to impart a limy taste than is a smooth mix- 

 ture. A good mixture properly added to and mixed with the 

 cream, and not in excess, is not nearly so likely to impart a limy 

 taste to the butter. 



A mixture of 3 pounds of lime to 17 pounds of water is the 

 same as 15 pounds of lime to 85 pounds of water, or a 15 per cent 

 mixture. 



