280 BULLETIN OE THE BUSSEY INSTITUTION. 
No. 25.— Huperiments on Feeding Plants with the Nitro- 
gen of Vegetable Mould. By F. H. Stormer, Professor 
of Agricultural Chemistry. 
In a paper* published in 1874 I insisted at some length upon the 
importance as plant-food of the nitrogen in vegetable-mould. 
Subsequently it occurred to me that the experiments recorded in 
that article might be made still more emphatic by mixing the 
vegetable-mould to be tested, not with mere sand and coal-ashes 
as then, but with a garden soil from which the whole of the 
original organic matter had been removed by careful calcination. 
Such earth would naturally contain all kinds of food needed by 
plants, with the single exception of nitrogen; and it was to be 
expected that plants would grow in it readily whenever the lacking 
nitrogen was supplied. It might even be possible to obtain in 
this way some quantitative indications of the value of the soil- 
nitrogen by proceeding methodically and mixing with weighed 
quantities of the calcined loam several definite, increasing amounts 
of the vegetable-mould to be examined. 
In order to test this idea, the following experiments were 
carried out in the glasshouse of the Bussey laboratory in the 
winter of 1877-78. A quantity of good dry loam from the garden 
of Mr. R. Beatley, Chelsea, Mass., was calcined at the tempera- 
ture of low redness in a large iron muffle capable of carrying 
two or three pounds of the material at a charge. For convenience 
and the saving of time spent in calcining, as well as for the sake 
of improving the texture of the rather too compact calcined earth, 
a quantity of Berkshire sand + was mixed with it before proceeding 
with the actual experiments.{ The experiments were made in 
wide-mouthed glass jars (preserve jars) in the same general way 
as the experiments previously described in this Bulletin.$ The 
mixtures of sand and calcined loam were made jar by jar; the 
amounts of materials recorded below being weighed out for each 
* “ Bulletin of the Bussey Institution,” 1. 252. 
+ See Bussey Bulletin, 1. 59. 
t As was done in an earlier series of experiments with roasted leather, 
described on page 61 of Vol. 2. of this Bulletin. 
§ Compare Vol. 1. pp. 54, 253. 
