and on training Fruit Trees. 439 



examine fairly any plant that is thus diseased, and their doubts 

 must be removed ; or let them establish the cause as described 

 with any healthy plant, and they will not be deceived by the 

 effect. 



We may also carry our comparisons still farther. It is 

 well known that animals which are fat, gross, and bloated, are 

 never safe and certain breeders ; and that is the case with 

 plants, and with parts of plants. A double blossom, or a large 

 quantity of leaves and stalks that are blistered, bloated, and 

 cankered, in a plant, is tantamount to a fat, gross, and bloated 

 animal; and every observant gardener may know that such 

 plants are never prolific or fruitful. Cucumbers and melons, 

 as they are commonly grown, bring but a very small portion 

 of the fruit they show to maturity ; and the cause is, their being 

 planted upon beds of dung. If a covering of slates, tiles, 

 stones, or boards, with their joints cemented, be placed between 

 the dung and the earth, and the earth be a well decomposed 

 and purified soil in which the plants are to grow, more than 

 double the quantity of fruit may be produced, under the same 

 lights, than by the common mode. The same principle ex- 

 tends to almost all plants ; the production of a large quantity 

 of stalk, branches, and leaves, and the production of flowers, 

 and fruit, are seldom found at the same time. 



As a due provision of the elements of vegetation is made 

 by nature, so is the combination and action of those elements, 

 in their progress from cause to effect, grounded and deter- 

 mined by certain laws of nature. Having then informed our- 

 selves what the elements are which nourish and sustain plants, 

 we must next acquire a knowledge of those laws of nature, as 

 without this we cannot exert any beneficial influence over the 

 growth and production of plants. 



I have explained and arranged those laws which I consider 

 to be immutable, in determining the growth and productions 

 of plants, in eight divisions : one of which is, that no plant 

 can produce blossoms or fruit, until it has made a certain pro- 

 gress in its growth, and acquired a surface of stalk, branches, 

 and leaves, duly proportioned to the food it consumes ; and 

 another, that the flow of sap in all erect-growing plants is 

 vertical, or directly opposite to that of the natural flow of 

 water. Thus, as water, when passing through a ramification 

 of vessels, will make its way into the lowermost first, and press 

 the most on the nearest downward openings, to make its exit ; 

 so will the sap of a tree make its way to the uppermost branch, 

 and press the hardest against the neai'est upward bud or open- 

 ing, to make its exit in the formation of fresh branches: in other 

 words, as water is impelled by gravitation, the sapof erect-grow- 



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