ft behind in the soil
manured with basic slag than in that manured with superphosphate of
lime. For example, if 100 lb. of super has the same effect in the first
year as 200 lb. of basic slag, and it is found that only 60 lb. of the
super and the basic slag have been assimilated the first year by the
plant, it is only natural to conclude that the remaining 140 lb. of the
basic slag will have a better after-effect than the remaining 40 lb. of
super. This has been actually proved to have been the case in
Professor's Wagner's experiments. The following are the results of some
experiments which Professor Wagner has carried out on the after-effects
of different manures:--

Out of 100 parts of phosphoric acid, there was removed by the first
year's crop--

Super 63
Peruvian guano 22
Bone-meal 7
Coprolites 6
Thomas-meal--
No. 1 fineness 39
No. 2 " 43
No. 3 " 15

Out of 100 parts of phosphoric acid left by the first crop, there was
removed by the three succeeding crops--

Super 30
Peruvian guano 9
Bone-meal 13
Coprolites 6
Thomas-meal--
No. 1 fineness 14
No. 2 " 29
No. 3 " 24

Numerous other experiments have been carried out by various
experimenters in different parts of Germany which it is unnecessary to
cite here. None, however, are so complete as those of Professor Wagner.

_Results of other Experiments._

In this country experiments have been carried out at Rothamsted,
Cirencester, Downton, Bangor, and by Dr Aitken at the Highland and
Agricultural Society's stations, as well as elsewhere. The results of
these various experiments naturally differ considerably, this being
owing to the difference in the nature of the soils upon which the
experiments were carried out, as well as the different degrees of
fineness of the slag used. They all, however, serve to confirm Professor
Wagner's general results. The results obtained in Scotland by Dr Aitken
at the Highland Society's stations were especially favourable to basic
slag as a phosphatic manure. The experiments were carried out on
turnips, and it was found that the Thomas-slag was, weight for weight,
superior to superphosphate. It may