448 The Neglect of Chemistry hj Practical Farmers. 



quantity of potash and sulphuric acid, and divide by 100, it will 

 give their respective amounts — 



Thus 73 X =40*15 i amount of potash contained in the 73 lbs. of 

 100 'I sulphate of potash ; 



and 73 X = 32"85 I amount of sulphuric acid contained in the 

 100 ' \ 73 lbs. of sulphate of potash. 



73*00. Amount of sulphate of potash given. 



In practice, of course, having obtained the amount of one con- 

 stituent, we should merely subtract it from the total amount of 

 the salt, and thereby obtain the amount of the other at once. 



Secondly, suppose it was desired to know how much sulphuric 

 acid of Sp. Gr. 1*85 would be required exactly to neutralize 

 50 lbs. of lime. 



Here, if we multiply the 50 lbs. by 49, the atomic v^^eight of 

 the sulphuric acid, of that specific gravity, and divide by 28, the 

 atomic weight of the lime, we obtain the result 87*5 lbs., as the 

 quantity of sulphuric acid of Sp. Gr. 1'85 required to neutralize 

 that amount of lime ; but if it was wished to know how much 

 sulphuric acid would be required to neutralize that quantity, the 

 answer by a similar process would be only 71*4 lbs., for the 

 simple mention of the name of an acid implies that it is in its 

 dry state ; and, in fact, the total amount of sulphate of lime 

 formed is the same in both cases, the excess in the total amount 

 (16'1) consisting of the water that was in combination with the 

 acid, and which, by the application of heat, might be expelled, 

 when the two results would exactly coincide. 



