364 BULLETIN OF THE BUSSEY INSTITUTION. 
upon Indian corn, had repaid its cost more than tenfold. Upon 
potatoes in particular he found that the muriate of potash generally 
did. good service, — the yield of tubers having been increased by it 
in nearly every experiment.* It was noticeable, however, that 
when used upon Indian corn the muriate of potash frequently failed 
to show much effect. In these experiments nitrate of soda used by 
itself seldom produced much effect, while plaster of Paris, though 
generally of little avail, sometimes showed marked results. Super- 
phosphate of lime by itself often did good service. There were a 
number of cases moreover where neither the nitrogenous nor the 
phosphatic nor the potassic manures were particularly useful. Mix- 
tures of the three kinds of fertilizers brought by far the largest av 
erage crops, and they were considerably better than those got from 
farm-manures. But the most profitable fertilizers were the partial 
ones, which fitted the demands of the special cases. Sometimes it 
was the plain superphosphate that gave the best return, sometimes 
the chloride of potassium, and sometimes a mixture of the two. 
As the average of twenty-six experiments with maize, chloride 
of potassium (that contained 50% of K,O), used at the rate of 200 
lbs. to the acre, gave an increase of 8.7 bushels of shelled corn 
over ‘‘no manure,” while superphosphate (of 16% P,O,), used at 
the rate of 300 lbs., gave an increase of 8.9 bushels, and nitrate of 
soda (of 16% N), used at the rate of 200 lbs., gave 5.8. The cor- 
responding averages drawn from nine experiments with potatoes 
were respectively 33.7, 24.6, and 4.3 bushels. As regards the 
kinds of soil most benefitted by the chloride of potassium, Pro- 
fessor Atwater says that on heavy (clayey) soils of the poorer 
classes it seemed to have a better effect than on the poor soils of 
lighter character, — whence his conclusion, already cited, that the 
muriate had a favorable action in loosening heavy soils by precipi- 
tating the gelatinous clay. 
It may here be remarked that Mayer has computed from the re- 
sults of forty-six field-experiments with chloride of potassium (of 
50% K,O) that 1 kilogram of this material has given an average 
increase of 24 kilos. of sugar-beets (380 kilos. of KCl having 
produced an average increase of 914 kilos. beets to the hectare of 
* A record of some interesting experiments with Stassfurt fertilizers on 
potatoes, which consist well with those reported by Professor Atwater, will 
be found in Lawson’s ‘‘ Ten Years of Gentleman Farming,” London, 1874, 
pp. 865, 871, 391; also in ‘‘ Transactions of the Highland and Agricultural 
Society for 1873.” 
