174' Quarteiiy Journal of Agricidttire. 



stem and branches, are treated of and illustrated by wood engravings in the 

 first three numbers; and No. IV. commences Agricultural Chemistry, with 

 an essay 



On the Atmosphere. — A very excellent paper. The heat of the air is 

 chiefly, if not altogether, produced by the rays of the sun ; and the tempe- 

 rature of a place depending on the quantity of sunbeams alighting u|)on it, 

 the temperature of the earth at different places, must be very different, be- 

 cause it is not a flat surface facing the sun, but a globe. Other circumstances 

 being the same, the heat produced is at a maximum, when the sun's rays 

 fail perpendicularly on the surface to be heated. F'or this reason the equa- 

 tor is warmer than the poles, the face of a hill than its back, and a southern 

 slope than a northern slope. But there are other causes which affect the 

 temperature of a place ; the denseness of the atmosphere over it, the con- 

 dition of the surface, and the character of the neighbouring countries or 

 seas. " If there be much marshy ground, wet land, or any condition of sur- 

 face calculated to charge the air with damp, the air will be comparatively 

 cold ; because, much damp in the air lightens it, and light air is with diffi- 

 culty heated. Water itself, too, whether in a liquid state or as a vapour, 

 is extremely difficult to be heated; and therefore both circumstances com- 

 bine to make wet lands cold lands. It is very interesting to observe how 

 beautifully the laws of nature operate to keep down such a state of things, 

 and how "kindly they combine with the husbandman, rendering his labours 

 to ameliorate the soil a means of ameliorating the climate also. That there 

 shall not be much air cold and very damp at the same time, is provided for 

 by the law, that the power of air to contain damp diminishes as its tempe- 

 rature falls. And that the climate shall be improved by improving the con- 

 dition of the soil, and the improvement of the soil, once effected, be for ever 

 kept up, is provided for by the same law. For, when the surface has been 

 drained, and the water run off to the sea, or gathered together in deep pools, 

 which present but a small surface compared with a field, and from which, of 

 course, a comparatively small evaporation can take place, then the average 

 temperature of the place rises, and its average power of taking up damp in- 

 creases ; so that though the same quantity of rain should fall in the course 

 of the year as before improvement, still the air will take it all up. and keep 

 the soil in good condition. Instead, then, of ascribing the foulness of our 

 pastures — the lateness and poorness of our crops — the stiffness of our land 

 — the miriness about the farm-yard — the wetness of the land — the coughs 

 and consumptions of the family, to the quantity of rain that falls, let the 

 ground be effectually drained, and the heart of the air will be wainned to- 

 wards the farmer. Rain will be sent in due quantity to refresh the fields, 

 but it will no longer be left in the furrows. The warm air will suck it up 

 as soon as could be wished. Without draining off the supei'fluous water, it 

 may be safely stated, that an elevation in the temperature of the air would 

 be productive of the most fatal consequences." 



On Emigration, by the Rev. Dr. Chalmers. — The author follows the line 

 of argument given in our review of Slane}' (Vols. I. and II.), clearly proving 

 that the rate of population in any country will depend on the standard of 

 enjoyment in the lowest class of societj', and that the schemes for relieving 

 the country, by transporting our surplus families to distant lands, is " one of 

 singular impotency and inaptitude," because it has no relation whatever to 

 the cause of the evil. " When the standard of enjoyment is low, as in Ire- 

 land, the tendency to increase in population must be great. When the 

 standard is higher, as in Scotland, marriages are later, and the land is less 



overburdened with the weight of redundant families Malthus's wisest 



remarks are to be found in his chapter on the Checks to Population in Nor- 

 way, where he alleges that the very want of many and distinct resources has 

 given such energy to the moral preventive check, as to have blessed that 

 country, in spite of its barrenness, with the most comfortable peasantry in 



