THE CLAYS. 649 
same plan as those of the New Jersey Report; though obtained by a 
different .process. In the first three columns will be found the three 
constituents of kaolin, in the fourth, their sum, giving the per cent. of — 
real clay in the body. In the fifth, sixth and seventh columns, are the 
sand, titanic acid and their sum, indicating the sterile impurities of the 
elay. In the eighth, ninth, tenth and eleventh, are iron, lime, magnesia, 
potash, soda and lithium, and twelfth, their sum, indicating the detri- 
mental or fluxing impurity of the clay; fourteenth, moisture, and 
fifteenth, sum total. 
The points wherein this report of an analysis is superior to the 
common method are: 
Ist. The amounts of true clay in a sample are seen at a glance, while 
it is not accessible at all in the other method. 
2nd. The sterile impurities can be separated and compared with the 
other properties of the clay. 
3rd. The fluxing impurities are expressed in detail and total, and 
can be considered individually or collectively in their-probable effect. 
4th. From a number of such analyses, conclusions may be drawn 
with ease and accuracy, which a less graphic method would fail to pre- 
sent to observation at all. © 
Method of Analysis. 
Weigh out 3 grams of finely pulverized and mixed clay into 
a platinum crucible. Fuse with sodic carbonate, disintegrate in cas- 
serole, acidulate, evaporate dry. ‘Take up in strong HCl, dilute, filter, 
wash, dry, ignite and weigh residue, which is the total silica. The 
filtrate, dilute, and divide into two solutions containing respectively one 
gram and two grams of clay. ‘Take the large solution, heat, precipitate 
iron and alumina with NH, HO and filter. Dissolve, precipitate in 
strong H, SO,, reduce with Zn and titrir with K, Mn, O,, which gives 
the iron. 
‘Take the smaller solution, take out iron and alumina as before with 
NH, HO. Boil out excess of reagent, filter, wash and weigh. From 
the weight, take out the iron already ascertained. The balance is 
alumina. 
In the hot ammoniacal filtrate, take out the lime with NH,O, filter, 
wash, ignite, and weigh as sulphate (Ca SO,). 
