supplement. SCIENCE AND ART OF AGRICULTURE. r295 



gation. Coal, iron, gypsum, and sandstone abound. The Canadas include an extensive territory, with 

 a climate which is on the whole salubrious. The thermometer, in summer, rises as lush as HO -"in the 

 shade, and in winter sinks below zero. The winter in Lower Canada is two months shorter than that 

 of Upper Canada. The geology of Canada is little known ; the principal rocks appear to be trap and 

 limestone. There are soils of every description, but the largest tracts are either alluvial, or of a Lighter 

 character, approaching to sand. Labrador, and the territory west of Hudson's Bay, Mr. M'Gregor does 

 not consider as suitable to emigrants. We can only refer the reader, who is desirous of emigrating. t<> 

 Mr. MGregor's book ; or to a very copious abstract of it which will be found in the Quarterly Journal 

 of Agriculture, vol. iii. p. 880. to 924. 



8058 — 1197. The culture of wheat in the West India Islands may be mentioned as a comparatively new 

 agricultural feature. The kinds which succeed best are the summer varieties, which have been cul- 

 tivated to advantage in Jamaica, Barbadoes, and several other islands. Great exertions have been 

 made with a view to introduce the best varieties into these islands from Europe, and to make known 

 the success which has attended their culture by Dr. Hamilton of Plymouth. (See Gard. Mag. and 

 Oard. Chron.) 



PART II. 



AGRICULTURE CONSIDERED AS A SCIENCE AND AS AN ART. (p. 208.) 



8059. — 12*5. The present state of agricultural science has been treated of in a prize Essay by 

 Dr. Madden, published in the Highland Society's Transactions in March 1842, from which, as taking the 

 latest and most comprehensive view of the subject, we submit the following abridgment : — 



To the question, " What has science done for agriculture ? " Dr. Madden answers that scientific ag- 

 riculture has been investigated by an extremely limited number of individuals, and this chiefly since the 

 commencement of the present century ; that a great draw back to the advance of agricultural science is 

 to be found in the want of confidence in it of practical men, and that among practical men there is a 

 great want of scientific knowledge. 



" If by the question, ' What has science hitherto done for agriculture ? ' we are to understand which 

 of the new improvements owe their origin to scientific investigation, we feel obliged to confess that as 

 yet we know of none extensively in operation. But if, on the contrary, we are to understand it in the 

 wider sense, as requiring an account of what science has effected towards establishing agriculture upon 

 a sure basis, so that the farmer may be enabled to apply his practical knowledge in whatever situation he 

 may be placed, and will be at once capable of determining what changes in his arrangements, &c. will be 

 necessary if called upon to change his farm, so that his operations will no longer be so much the sport of 

 chance that each farmer can be considered as knowing only the treatment fitted for his own farm, we 

 can confidently assert that much, very much has been accomplished; and although there is no point 

 upon which we have as yet by any means perfected our knowledge, still there is scarcely any upon which 

 science has not already "thrown sufficient light to enable those, who are at all capable of appreciating her 

 services, to derive great benefit and direction in cases of difficulty." To prove this, he takes a general 

 view of what science has effected under the heads of, 1. Soil ; 2. Effects of Vegetation upon soil ; 3. The 

 Art of Culture, and 4. The Economy of Husbandry. 



806U. 1. Soil. Science has already proved, in the most satisfactory manner, the following circum- 

 stances regarding soil : — 



8061. In order that it may be fertile, it must contain all the mineral matters found in the ashes of the 

 plants destined to be cultivated upon it, in such a condition as to be available by the plants, and in suffi- 

 cient quantity to enable the supply to be kept tip by some economical mode of cultivation. " The necessity 

 of this condition depends upon the well-established fact, that plants cannot make for themselves any of 

 the elementary substances which they contain, but are only capable of changing the form in which these 

 are combined with one another. Thus, the organic portion of plants, or that which is destructive by fire, 

 is composed of four elementary substances ; namely, carbon, or charcoal, and three gases, named oxygen, 

 hydrogen, and azote. Now plants cannot produce any of these four substances under any circumstances 

 whatever; but if they are supplied with them, in almost any state of combination, they can. by their vital 

 processes convert them into starch, gum, woody fibre, or whatever else they may require. The same is the 

 case with the constituents of their ashes, They must be supplied with the requisite elements in some state 

 of combination, and then they will be able to produce for themselves the particular compound which they 

 require." Dr. Madden admits that a considerable increase of knowledge is required among farmers 

 before this part of agricultural science can be brought to perfection ; though he believes that much of 

 the future progress of agriculture depends upon increased knowledge in this department of agricultural 

 chemistry. 



8062. — 2. Soil must consist of a due admixture of impalpable matter and larger sized particles, so that it 

 may be porous and easily permeable by air and moisture, while, at the same time, there is a sufficient su/i- 

 ply of matter in a state capable of undergoing chemical changes. " All the useful organic matter of soil is 

 in a combination with the impalpable earths which it contains ; though the larger particles are necessary 

 for the admission of air and water. Till these larger particles are reduced to powder, they exert no direct 

 influence whatever upon the vegetation of the soil of which they form a part." 



8063 3. Soil must contain a sufficient supply of organic matter mingled with it in a state capable of 



decomposition by the action of air and water. " In general, the quantity of vegetable and animal matter 

 in a soil is a direct index of its fertility." 



8064 4. Soil, to be fit for profitable cultivation, must be free from any mineral substance which is 



destructive of fertility. " This is a case in which no farmerwill doubt the utility of chemical knowledge; 

 thus, if the injurious matter bean acid or a soluble salt of iron, it may he neutralised by lime ; or if it should 

 be some compound of magnesia, it may be rendered innoxious by exposure to the atmosphere." 



8065.— 5. Soil must be capable of being reduced to a sufficiently fine tilth, without an undue amount of 

 labour, in order that its culture tnay be profitable. 



8066 6. Soil for a good farm ?nust either be 7iaturally capable of letting off 'any superabundance ■>/ 



wa'er, or it must becapable ofbeing made to doso artificially by draining. " The advantages of draining 

 a soil naturally moist can hardly be over rated. It not only admits air to the roots of plants, but admits 

 the temperature of the atmosphere, so that a drained soil will always be found to produce an earlier 

 vegetation than the same soil undrained." 



8067 7. Soil, to be useful to the cultivator, must possess a structure which will allow /he decomposition 



of organic matter mingledwith it to proceed at a regular rate, being neither so fast as to waste the manure, 

 nor so slow as to keep it too long fresh. " Hence gravels, coarse sands, or strong clays, are to be improved 

 by the addition of soils of an opposite texture, by the use of suitable manures, and by appropriate me- 

 chanical treatment ; such as exposing strong clays to the frosts of winter, or the intense heat of summer, 

 compressing loose gravels or sands, &c." 



8068 8. The situation of soil must be such as to admit of all the operations of husbandry being per- 



