B22 
So quickly did the phosphoric acid come through in the drainage 
water in experiment No. 1, that I was led to pass water through a 
portion of the soil, to see whether phosphoric acid could be washed 
out of the soil itself. The result is given in experiment No. 2. 
Experiment No. %. 
A small fiber flask was filled with earth like that used in experi- 
ment No. 1, and water run upon it. After a short time traces of 
phosphoric acid were found and continued in the drainage so long as 
water was passed through. 
Experiment No. 3. 
Another portion of the garden soil was thoroughly dried for sey- 
eral days. The moisture and such other volatile matter as was pres- 
ent must have been pretty largely driven off. | 
A second jar was filled with this. Nine pounds being used 11000ce. 
of distilled water was passed through and no traces of phosphoric 
acid found in the drainage. 
Distilled water charged with carbonic acid was then used and soon 
traces of phosphoric acid were found in the drainage. When 1500cc. 
had been passed through, the supply was shut off for 36 hours, after 
which it was again resumed, and the first drainage to come through 
gave a heavy precipatate of phosphoric acid. 12000cc. of carbonic 
acid water was run through, and at this stage considerable acid was 
present, and continued so long as the experiment continued, 
The result obtained in experiment No. 8 differs from those of Nos. 
1 and 2; particularly No, 2, where we obtained phosphoric acid in 
the drainage water on passing distilled water through the soil. 
We should bear in mind, however, that the soil, although of the 
same nature, was not treated under like conditions. 
That in No. 2 was air dried and still contained a large per cent. of 
moisture while the portion used in experiment No. 3 had. been thor- 
oughly dried for several days. | 
We find also that when water charged with carbonic acid was used 
in experiment No. 3 phosphoric acid came through in the drainage. 
Inexperiment No. 1, when P, O, had ceased to exist in the drain- 
age, carbonic acid water again liberated it so long as the experiment 
was continued. Indrying the soil, whatever change may have taken 
place, it was sufficient to drive off, or render nonactive, the agent 
which had previously forced the phosphoric acid from the soil into 
the drainage water. The supplying of distilled water charged with 
carbonic acid to this same soil gave us results agreeing with those 
obtained from soil that had not been so dried and containing 11.25 
per cent. of moisture. 
Experiment No. 4. 
A third jar was filled with dry earth as in experiment No. 3. 
Spring water was supplied to this; 9000cc. of percolations gave no 
phosphoric acid. 50cc. of a solution made from Bowker’s Alkaline 
phosphate was added to 1000ce. of spring water and allowed to flow 

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