70 



AGRICULTURAL CHEMISTRY. 



This soil does not suffer from want of 1 it, in such a manner that they were not ex 

 drainage : it is well exposed to the sun, is I hibited by analysis. 



in an elevated situation, and in a good state Oats and barley were sown on this land 

 of cultivation. In order to ascertain whether I the second year after being reclaimed, and 

 the rust was due to the constituents of the both suffered much from rust, although dif- 



soil, (phosphate of iron ?) or to certain for- 

 tuitous circumstances unconnected with 

 their operation, a portion of the land was 

 removed to another locality, and made into 

 an artificial soil of fifteen inches in depth. 

 Upon this barley and wheat were sown ; but 

 it was found, as in the former case, that the 

 plants were attacked by rust, whilst barley 

 growing on the land surrounding this soil 

 was not at all affected by the disease. From 

 this experiment it follows, that certain con- 

 stituents in the soil favour the developement 

 of rust. 



13. Soil of a heath, which had been 

 brought into cultivation in the vicinity of 

 Brunswick. The analysis was made before 

 any kind of crops had been grown upon it. 

 Corn-plants were first reared upon the new 

 soil, but were found to be attacked by the 

 rust, even on those parts which had been 

 manured respectively with lime, marl, pot- 

 ash, wood ashes, bone-dust, ashes of the 

 heath plant, common salt and ammonia. 

 100 parts contain : 



Silica with coarse siliceous sand 

 Alumina - - - - 

 Protoxide and peroxide of iron in combina- 

 tion with phosphoric and humic acids 

 Protoxide and peroxide of manganese 

 Lime in combination W'fh humus - 

 Magnesia idem - - ,, * 



Potash and soda ... 



Phosphoric acid - - 

 Sulphuric acid . - 



Chlorine ------ 



Humus soluble in alkalies - 

 Rssinous matters - 



Coal of humus and water 



51-337 

 0-528 



0-398 

 . 0-003 



0-230 

 . 0-040 



o-oio 



0-066 

 0'022 



0-014 

 13-210 



2-040 

 32-100 



100-000 



The next analysis represents the soil after 

 being burnt. 100 parts by weight of the soil 

 left after ignition only 50 parts. 100 parts 

 of these ashes consisted of: 



Silica and siliceous sand 

 Alumina : 



Peroxide of iron ----- 



Peroxide of manganese 

 Lime in combination with sulphuric acid 

 Magnesia combined with silica 

 Potash and soda - 



Phosphoric acid (principally as phosphate of 

 iron ------ 



Sulphuric acid 



Chlorine 



100-000 



By comparing this analysis with the one 

 which has preceded it, an increase in cer- 

 tain of the constituents is observed, particu- 

 larly with respect to the sulphuric acid, pot- 

 ash, soda, magnesia, oxide of iron, oxide of 

 manganese, and alumina. From this it fol- 

 lows, that the humus, or in other words, the 

 vegetable remains, must have contained a 

 quantity of these substances confined within 



ferent pans of the soil were manured with 

 marl, lime and peat-ashes; whilst other por- 

 tions were left without manure. In the first 

 year, all the different parts of the field pro- 

 duced potatoes, but they succeeded best in 

 those divisions which hid been manured 

 with peat-ashes, lime and marl. In the 

 second year, oats mixed with a little barley 

 were sown upon the soil ; and the straw 

 was found to be strongest on the parts treated 

 with peat-ashes, lime, marl, and ashes of 

 wood. Red clover was sown on the third 

 year; it appeared in best condition on those 

 portions of the soil manured with marl and 

 lime. Upon the divisions of the field which 

 had been left without manure, as well as on 

 those manured with bone-dust, potash, am- 

 monia and common salt, the clover scarcely 

 appeared above ground. The divisions ot 

 the field, which had been manured in the 

 first year with peat-ashes, ammonia, and 

 ashes of wood, were sown with buckwheat 

 after the removal of the first crop of clover. 

 The buckwheat succeeded very well on all 

 the divisions, yet a marked difference was 

 perceptible in favour of the portion treated 

 with ammonia. These experiments show 

 us, that a dressing of lime did not completely 

 remove from the soil its tendency to impart 

 rust to the plants grown upon it. Never- 

 theless it is highly probable, that as soon as 

 the protoxide of iron became converted into 

 the peroxide by exposure to the atmosphere, 

 lime would possess more power in decom- 

 posing the phosphate of iron. 



14. Subsoil of a loamy soil in the vicinity 

 of Brunswick. It is remarkable from the 

 circumstance that sainfoin cannot be culti- 

 vated upon it more than two or three years 

 in succession. The portion analysed was 

 taken from a depth of five feet. 100 parts 

 contained: 



Silica with very fine siliceous sand - 90'035 

 Alumina - - - - - 1'976 



Peroxide of iron ----- 4'700 



Protoxide of iron T115 



Protoxide and peroxide of manganese - - 240 



Lime ' 0'0'?2 



Magnesia O'llS 



Potash and soda - - - _ - - 0'300 

 Phosphoric acid, combined with iron - 0'098 

 Sulphuric acid (the greatest part in combina- 

 tion with protoxide of iron) 1 '399 

 Chlorine ... a trace 



100000 



Now the results of the analysis give a suffi- 

 cient account of the failure of the sainfoin. 

 The soil contains above one per cent, of 

 sulphate of protoxide of iron (green vitriol 

 of commerce,) a salt which exerts a poison- 

 ous action upon plants. Lime is not pre- 

 sent in quantity sufficient to decompose this 

 salt. Hence it is that sainfoin will not thrive 

 on this soil, nor indeed lucerne, or any other 



