THE FARMER'S MAGAZINE. 



THE ATMOSPHERE AND THE SOIL, 



BY CUTHBEUT W. JOHNSON, ESQ., F.K.S. 



While the rain pours down upon our fields, as of 

 late, in unusual quantities, our attention becomes 

 more directed to the effect it produces on the soil, 

 and to the good results of drainage. We have, 

 indeed, more than one reason for cultivating such 

 trains of thought : we are ever rewarded, in these 

 studies, by not only the interesting knowledge we 

 acquire, but by the profitable answers which Na- 

 ture so often returns to our inquiries. 



It may, then, be practically useful, if, in this wet 

 season, we commune together a little upon these 

 things — if we glance at the origin of our copious 

 rainfalls, and consider how much distant countries 

 unconsciously contribute, in this way, to each 

 other's welfare — before we proceed to remark the 

 results of some recent valuable observations on the 

 effects produced by the presence of water, and the 

 action of the atmosphere, in drained and undrained 

 soils. 



It is, indeed, as a writer in the North British 

 Review recently remarks, only the breezes of the 

 encircling air which flows above and around us, 

 that makes the whole world kin. The carbonic acid 

 with which to-day our breathing fills the air, to- 

 morrow seeks its way round the world : the leaves 

 of the date-trees which grow around the Falls of 

 the Nile, will drink it in ; it will add to the stature 

 of the cedars of Lebanon ; the cocoa-nuts of 

 Tahiti, the palms and bananas of Japan, will 

 change it into flowers. The oxygen we are breath- 

 ing was distilled for us some time ago by the 

 magnolias of the Susquehanna ; and the great trees 

 which skirt the Orinoco and the Amazon, the giant 

 rhododendrons of the Himalayas, the roses of 

 Cachmere, the cinnamon-trees of Ceylon, the deep 

 forests of Central America contributed to it. The 

 rain we have seen descending so copiously was 

 exhaled for us from the warm surface of the ocean 

 — was thawed for us out of the icebergs which 

 have watched for ages the polar star. 



The amount of that rain, in Surrey (where the 

 average fall is about 24 inches : it was only 17.94 

 inches in 1858, and 22.25 in 1857), was about 20 

 inches in the last six months of 1859, and has been 

 about 29 inches to December 1, in I860, as will 

 be seen from the following table, which shows— 



The Rainfall at Croydon, 250 Feet abo\-e the Level 

 OF THE Sea, IX the Years 1859-00. 



1859. 1860. 



January .... 0.89 . . . 2.-15 



February .... 0.78 ... l.OO 



March 1.06 . . . ].,SS 



April 2.36 ... ],-i5 



May 274 _ _ _ j^ ,35 



June 1.G2 . . , 5.81 



July 4.69 . . . 2.65 



August 1.00 ... 299 



September . . . 1,90 . . , 8.00 



Oclober .... 8.88 ... 1.97 



November . . . 2.05 , . . 2.7,0 



December , . . 2.17 to tlie iwtli l!l8 



29.04 



With such widely-differing depths of rain, we 

 need hardly add, how very interesting to the 

 farmer is the proportion of these varying amounts 

 of rain-water which his land-drains have to con- 

 duct away! This has been carefully determined on 

 different kinds of soil — as on the chalk formation 

 of Hertfordshire, by Mr. Dickson and Mr, Parkes 

 (Jour. Roy. Ac/. Sac, vol. v., p. 151) ; on the lime- 

 stone formation of Yorkshire, by Mr. C. Charnock 

 (Ibid, vol. x., p. 516) ; and on the London Basin 

 clay and the gault, by Mr. J. B. Denton {Ibid, vol. 

 XX., p. 273) : and, in the course of these valuable 

 observations, both Mr. Parkes and Mr. J. B. 

 Denton had their attention drawn to several 

 curious effects produced by the removal of the 

 land-water on the temperature of the soil. 



The rainfall in Hertfordshire, during eight 

 years, is given by Mr. Parkes in the following 

 table, in tons. By this record the farmer will see 

 how much the relative evaporation and filtration 

 of the rain-water varies at diflferent seasons of the 

 year, and, as might be reasonably concluded, its 

 annual amount also ; and he will note that, in 

 practice, almost all the filtered portion must either 

 be removed by drainage, or will remain as land- 

 water, dissolving the saline matters, and in several 

 other ways impairing the fertility of the soil ; 



April to Sept., incl. Oct. to March, iucl. 

 Filt. Evap. Filt. Evap. 



1836 .. 212 1,023 .. 1,574 330 



1837 .. 10 9S2 .. 003 4.52 



1838 .. 12 1.082 .. 855 393 



1839 .. 263 1,500 .. 1.240 159 



1840 .. — 980 .. 829 362 

 1811 .. — 1,544 .. 1,437 269 



1842 .. 131 1,099 .. 1,059 387 



1843 .. 100 l,8-.i2 .. 720 538 



Mean.. 91 1,102 1,052 360 



Of the several injurious effects of leaving the 

 soil soakmg in water, the lowering of its tempera- 

 ture must be regarded as one of the chief. The 

 different temperature of a drained and the adjoin- 

 ing undrained soil, was ascertained by Mr. Parkes 

 on another kind of land — viz., the deep peat of 

 Chat Moss, in June, 1837 {Ibid,vo]. v., p. 141). He 

 ascertained that, although the constant temperature 

 of the natural bog, surcharged with water from 12 

 inches to 30 feet, was 46 deg., and the thermometer 

 planted in the same substance at 7 inches deep 

 constantly indicated 47 deg., yet that in a portion 

 of the same bog, well drained and deeply stirred, 

 at a depth of 31 inches, it indicated a maximum 

 temperature of 48^ deg., having gradually gained 

 2J deg. ; and that in such well-prepared soils the 

 action of the atmosphere is much more considerable 

 and rapid than is commonly believed, is shown by 

 the observation made during the same valuable 

 experiments, that, although the temperature of the 

 natural, unstirred soil at a depth of 7 inches, was 

 only 46 deg., yet that the mean temperature during 

 36 observations of the stirred and drained soil was 

 10 deg. higher, and that after a thunder-storm it 



