136 BOARD OF AGRICULTURE. [Pub. Doc. 



Lawes and Gilbert's experiments indicate that soluble phos- 

 phoric acid serves two purposes, — one to supply the needed 

 phosphoric acid for plant growth, and the other to assist in the 

 assimilation of other plant food ingredients ? jSTow, in your 

 opinion, does phosphoric acid in this form tend to hasten ma- 

 turity because it helps the assimilation of other plant food 

 elements ? 



Dr. VooBHEES. That's very true, but that would be nor- 

 mal ripening, however. It would not be abnormal ripening, 

 and it would not hasten it in the sense that it would not 

 ripen before it ought to ripen. 



Mr. BowKER. Does not soluble and reverted phosphoric 

 acid have a catalytic action in the soil ? In other words, is it 

 not a fertilizer and a " catalyzer " as well ? I think it is very 

 important to have soluble phosphoric acid, and plenty of it, 

 in a tobacco fertilizer, not only to supply the required phos- 

 phoric acid, but to hasten maturity. We know that in grow- 

 ing Indian field corn an excess of available phosphoric acid is 

 essential. Exj^erience has shown this, although science may 

 not have shown the reason why. Science should and usually 

 does lead, but in some cases it has not caught up with the 

 procession. Liebig, the father of commercial fertilizers, dis- 

 covered, as you know, that superphosphate of lime was much 

 better than undissolved phosphates or undissolved bone. The 

 great chemical fertilizer industry was founded upon dis- 

 solved bone, carrying about 2 per cent of nitrogen and 12 

 per cent of soluble phosphoric acid, no potash. This fer- 

 tilizer was used chiefly in ISTew England in the hill for corn, 

 and to this day farmers buy it with a little potash added 

 to push and hasten maturity. I believe science will prove, 

 if it has not already done so, what experience has discovered, 

 — that soluble and reverted phosphoric acid serves two of- 

 fices in the soil, that of food supply and that of assisting in 

 assimilation. 



Dr. VooRHEES. The application of phosphoric acid sim- 

 ply made the conditions more nearly normal for the devel- 

 opment of the corn plant. The plant needed more phosphoric 

 acid to enable a normal growth. 



