18 



CULINARY OR KITCHEN GARDEN. 



that means must be employed for their 

 restoration. This is to be effected by 

 what are usually called mineral manures, 

 or by the aid of such vegetable ones as 

 may contain them all or in part. 



Should, however, the recent discovery 

 made by M. Barral, a French chemist of 

 great respectability, prove to be correct — 

 and of that there appears to be little 

 doubt — these ingredients, annually ab- 

 stracted from the soil, are given back or 

 provided again in a way and to an ex- 

 tent hitherto unsuspected. Chemists long 

 ago had determined that the air we breathe 

 consisted only of two distinct gases, oxy- 

 gen and nitrogen, with a minute propor- 

 tion of carbonic acid dispersed through 

 a variable quantity of aqueous vapour. To 

 these Liebig added carbonate of ammonia 

 as constituting the essential parts of the 

 whole, considering the minute traces of 

 lime, potash, and common salt, as too 

 insignificant to deserve notice. This cele- 

 brated chemist still further held as quite 

 secondary and insignificant the presence 

 of nitric acid, the action of which is so 

 important in conveying nitrogen to the 

 vegetable system, and declared the quan- 

 tity as being too small to be even esti- 

 mated in the rain of thunder-storms. M. 

 Barral has, however, shown this in a dif- 

 ferent light. The following explanation 

 of his experiments, with remarks by the 

 editor, appears in a very recent number of 

 " The Gardeners' Chronicle," 1853 : " This 

 eminent chemist was led, during the last 

 six months of 1851, to examine minutely 

 the water collected in the rain-gauges of 

 the Observatory at Paris. His mode of 

 investigation is declared by Messrs Dumas, 

 Boussingault, Gasparin, Regnault, and 

 Arago, names foremost in French science, 

 to be free from all objection, and to bear 

 the most severe counter-trials to which 

 they could expose it. M. Barral states, 

 that although the quantities of the fol- 

 lowing substances varied in different 

 months, yet the monthly average, from 

 July to December inclusive, was as fol- 

 lows : — 



Substances in a cubic metre of Main Water. 



Nitrogen, 8.36 grammes — 129. grains. 



Nitric acid, 19.09 „ — 294. „ 

 Ammonia, 3.61 — 55.7 „ 



Chlorine, 2.27 „ — 35. „ 



Lime, 6.48 „ — 100. 



Magnesia, 2.12 „ — 32.7 „ 



" He did not ascertain whether all these 

 substances are contained in rain-water 

 collected at a distance from towns. But 

 Mr Bence Jones found at least nitric 

 acid in rain-water collected in London ; 

 at Kingston, Surrey; at Melbury, Dorset- 

 shire; and, far from any town, at Clona- 

 kelly, in Ireland. If we assume that M. 

 BarraPs averages represent what occurs 

 on an English acre, the quantity of such 

 substances deposited on that extent of 

 ground may be safely estimated as fol- 

 lows. The average depth of rain which 

 falls in the neighbourhood of London is 

 well ascertained to be about 24 inches per 

 annum. This is at the rate of 87.120 

 cubic feet, or 2466 cubic metres of rain- 

 water per acre ; and this, according to the 

 proportions per cubic metre in the pre- 

 ceding table, would afford annually of — 



Nitrogen, . . . . 45| lb. 



Nitric acid, . . . 103 „ 



Ammonia, . . . . 19^ „ 



Chlorine, . . . . 124 „ 



Lime, .... 35 „ 



Magnesia, . , . . 11 „ 



Annual total per acre of these ) 



ingredients returned to the ( 99( _ 



soil by the agency of rain f « 

 alone, ) 



" Of these substances, the three first are 

 of the utmost importance, on account of 

 their entering so largely into the indis- 

 pensable constitution of the food by which 

 vegetable life is sustained. The quantity 

 of ammonia thus ascertained to exist is 

 about what is expected in 2 cwt. of Peru- 

 vian guano ; and bountiful nature gives 

 us, moreover, nearly 150 lb. of nitro- 

 genous matter, also suited to the nutrition 

 of our crops. Nature gives us food, and 

 we improvidently waste it. What with 

 shallow cultivation on the one hand, hard 

 ill-tilled land, puddled furrow-trenches, 

 and polished furrow-slices, rain-water, thus 

 highly charged with the most nutritious 

 ingredients, either runs off to ditches, 

 or is so ill directed that it very imper- 

 fectly reaches the roots. On the other 

 hand, by means of close cropping, that 

 which is intended to bathe every part of 

 a plant, and to be instantly absorbed by 

 its verdant surface, is as completely turned 

 aside as if two-thirds of the crop grew 

 beneath a penthouse." 



From this it will be seen that nature is 



