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1922] EATON—SULPHUR CONTENT OF SOILS 41 
to see what results have been obtained from using sulphur as a 
fertilizer in these regions. Very little work of this kind has been 
done. Several stations report a favorable effect from using phos- 
phorus or potassium as a fertilizer for alfalfa, when the carrier of 
the phosphorus or potassium also contained sulphur. The Dela- 
ware station (7), for example, reports greatly increased yields of 
alfalfa due to acid phosphate. Experiments in Oregon (21) have 
shown a decided increase from applying acid phosphate to soils, 
but no increase due to phosphorus in any other form. Here it has 
been definitely proved that the increased yield caused by acid 
phosphate was due to the sulphur of the acid phosphate, and not 
to the phosphorus. It would seem worth while to test this in the 
case of the Delaware soils. The Virginia station (3) secures 
increased yields of alfalfa due to phosphorus in the form of acid 
phosphate and basic slag, but not in the case of other forms of 
phosphorus, such as rock phosphate. Here again we have the 
possibility that sulphur is responsible for the increased yields. 
The Massachusetts station (16) finds sulphate of potash a better 
fertilizer for alfalfa than muriate of potash. The alfalfa of the 
sulphate of potash plats was also a darker green. Clearly these 
results are due to the sulphur present in the sulphate of potash, and 
not to any differences in the potassium. 
The best experiments on the Atlantic coast to show the effect 
of sulphur fertilization on crops are those of the investigators of the 
colonial period, whose work is summarized by CROCKER (4). 
PETERS and Binns were the most prominent of these investigators. 
They performed numerous experiments showing the effect of 
Sypsum on crop yield. Leguminous crops especially were benefited, 
red clover giving increased yields of two to threefold. Binns 
Teported like increased yields for corn and wheat. Although the 
Teports of the experiments do not make this clear, it seems likely 
that the beneficial effects of gypsum on the non-leguminous crops - 
was due to the increased nitrogen supply brought about by the 
Sreater growth of the legumes of the rotation. RUFFIN was also 
greatly impressed by the results obtained from the use of gypsum 
as a fertilizer. In his Essay on calcareous manures he speaks of the 
magic effects obtained from applying gypsum as a fertilizer to 
