238 AGRICULTURAL EXPERIMENTS. 
to be able to arrest the phosphoric acid during its per- 
colation through the soil after rains, thus only a small 
quantity of itcame into actual contact with the roots of 
the barley.” In Ceylon soils, oxide of iron would arrest 
the phosphoric acid. ‘‘ This of oourse was different in 
the cases of experiments (5) (6) and (7) where part 
at least of the phosphoric acid was supplied in the 
insoluble form, and larger yields were the result. 
With regard to experiment (8) the authors do not ex- 
plain whether the remarkable yield obtained was the 
result of the way in which the phosphoric acid was com- 
bined or of the presence of potash”: the latter I should 
think. 
‘‘ Manuring £xperiments with Oats. By C. Jenssen 
(Bied. Centr. 1879). A field was marked off into eleven 
plots of 975 square metres each ; of these, two were not 
manured, the remaining nine being treated with quan- 
tities of manures of various sorts equal in value com- 
mercially. The table following shows the various 
manures used and the resulting produce :— 
‘Quantity applied per Hectare Grains. Straw. Chaff. 
Kilos. Kilos. Kilos. Kilos. 
Chili Saltpetre ... son BLD 201 268 29 
Unmaxured ae eo 151 190 18. 
Bone Meal a pe. WeZS 181 227 21 
Bone Meal Superphosphate 25 173-216 21 
Ammoniacal Superphosphate 22 Ae OD 20 
Peru Guano if ot. SENG 181 209 17 
Unmanured ae LB oes 168 194 16 
Bone Guano Superphosphate 31 194 242 17 
Animal, Manure ... Le TES 172 2s 18 
Stable Dung hie ... 1100: 194 233 23 
Mejellon Guano Superphos- 
phate 29°5 170 =200 14 
‘‘The above table shows that Chili saltpetre, and next 
to it, stable dung and bone guano superphosphate, pro- 
duced the best yields. Further researches are necessary 
to establish any conclusions from the above.” 
** Absorptive Power of Soil Constituents for Gases. 
By G. Ammon (Bied. Centr. 1879). The substances used 
in these experiments were sand, kaolin, carbonate of 
lime, hydrated oxide of iron, gypsum, clay, and humus, 
all powdered to various degrees of fineness. The author 
tried the effect of aqueous vapor and ammonia on these 
substances at various. temperatures; his experiments. 
shewing that the most favourable temperature for absorp- 
tion lay between 0° and 10° c.: and that the quantity 
absorbed varied directly with the finenesss to which the: 
substance had been powdered. 
‘* The following are the numbers obtained, 100 cubic: 
centimetres of each substance being used, and the water 
being calculated by volume in state of gas.” 
