84 
been creditably informed; that a red ocher of iron , called reddle,* * * § has been 
used on some lands with advantage in the north of Staffordshire. 
EXPERIMENT XLVL 
Humboldt made experiments with the muriatic, t nitric,X and sulphuric 
acidd,% pure; and mixed with water; and he found that these produced no 
sensible effect in promoting germination. 
The reason of which appears to be this: The oxygen of these acids is too 
firmly attached to their respective radicals; to be disengaged; and act on the 
affinities presented them by the vegetable fibre. 
CONCLUSIO N. 
Hence we presume; we may be warranted to conclude; that oxygen 
when combined with certain radicals has a great effect in accelerating the 
proceed of germination . II 
* Reddle, or Red Chalk, is a calciform ore of iron, termed in the new nomenclature; the yellou) 
oxyd of iron. 
f For an account of the muriatic acid, vide note (*), page 79 . 
+ The nitric acid is liquid, white, caustic, of a strong and nauseous smell, and is formed of azot 
and oxygen. The nitrous acid is the same as the nitric acid, except in having a smaller portion of 
oxygen, and is composed of one part azot, to three parts oxygen, which was first discovered by the 
Hon. Mr. Cavendish, who put three parts oxygen air, to one of azot, into a bell glass, and by passing 
the electricJire through that mixture, caused them to combine, and hence produced the nitrous acid; 
such are the wonderful changes resulting from a new combination of simple elements! 
§ 1 he sulphuric acid is formed of sulphur and oxygen, by the combustion of sulphur; it is in¬ 
odorous, and twice as heavy as water. The sulphureous acid only differs from this in containing less 
oxygen, but has, on the contrary, a very powerful smell. 
II This subject will be resumed when we come to treat on the Principles of Agriculture, when we 
shall relate at length the experiments of Hr. Ingenhousz, who proposed to the Board of Agriculture a 
scheme of quickly oxygenating, by means of acids, the earth, to prevent the necessity of fallowing; 
and he obtained the Gracious Permission of The King, who has ever with parental solicitude encouraged 
the plough, to try these experiments upon any part of the land cultivated by His Majesty. 
