BULLETIN OF THE BUSSEY INSTITUTION. 259 
Compare the results recorded in the table below, where the plants 
were fed with potash and phosphoric acid. 
It has already been shown, on pages 63 and 65, that good crops may 
be got from the sterile Berkshire sand, by adding to it the various ele- 
ments of plant-food ; and the same remark is true of the mixtures that 
contained kaolin and pipe-clay in the present set of experiments. 
These facts are of course no more than particular instances of the well- 
known truth, that has often been illustrated, that several kinds of food 
are needed by plants, and that the absence of either of them is fatal to 
the life of the plant. But the figures of the last table, on being com- 
pared among themselves and with those of the tables on pages 54 to 
65, show clearly that the loams and peats of jars Nos. 1 to 5 afforded a 
very considerable supply of each of the elements of food needed by 
the plants that were grown upon them. 
For the present it concerns us particularly to remark that nitrogen 
was supplied to the plants in abundance by each of the peats and 
loams. The significance of this fact will appear even* more clearly on 
The Crops 
The Jar contained a 
mixture of Sand (see | Weighed Craw ta 
page 258) and in grms. | yeicht in 4 Remarks. 
(Dried at inches . 
90° to 100°.) ; 
Plain-field Earth . 
Loam from Mr. Apple- 
ton’s Broadfields Farm GS 
Loam from Mr. Salton- 2 oe The plants were 
stall’s Pasture... ; very green, and 
not nearly ripe 
’ when harvested. 
Bussey Peat. . 
Dabney Peat 
Bt OE 
ue nd 
Only 2 plants, not 
yet ripe. 
flowers 
Kaolin. . 34 | Only 2 plants. 
Pipe Clay 
Ct 
me te 
ee ee 
tu dt vd te ud 
Sand alone ... 
* Only two plants. 
