138 ANDREAS KURTZ 



carb. of lime, these are mixed and melted 

 together, and afterwards mixed with i2^oz. 

 of white lead and ground together." 



In August, 1837, there is a note on "alum 

 operation." To prepare sulphate of alumina. 



IOO of calcined clay (called crackling clay), 

 IOO of brown sulfuric acid, 



50 of water, dissolve by heat, then add 

 400 more water and let it settle, it will produce 

 550 Ibs. of liquor at 20 sp. gr. called A liquor. 



Ammonia liquor at 15 sp. gr. from borax 

 operations, I call B liquor. 



I take 400 of A with 200 of B, and bring 

 it to a boiling point and crystallise it, I 

 obtained 150 of alum in fine crystals, the 

 mother liquor from this gives 10 sp. gr. 



William Joseph found in the large way that 

 i ton of calcined clay, in i ton of brown acid 

 gives generally 2*^ tons of alum." 



The book closes with experiments on 

 "Essence of oil of rosin, naphthas, rectified 

 spirit, mastic, sandarac, india-rubber, shellac, 

 copal, etc." 



This review enables us to perceive how 

 numerous and varied were the researches and 

 investigations which he personally made. He 

 used to live in his laboratory ; if he had any- 



