626 Retrospective Criticism. 



with the exception of E. tortulaeflora : this latter I have tried twice, but 

 without success, but I did not put more than three or four cuttings in, 

 each time. 



I have been induced to trouble you with this communication, in the hope 

 of inducing some of your readers to become growers of Cape heaths, feel- 

 ing satisfied in my own mind that they may be cultivated with the same 

 ease, and with less trouble, than is bestowed upon some plants much less 

 interesting, and less worthy of notice. Should you be of opinion that the 

 above observations are likely to forward such a result, you will, perhaps, 

 be good enough to give them insertion in your Magazine, which will much 

 oblige, yours, &c. — E. London, May 3. 1833. 



On exposing the Cape Heaths to the open Air of Britain during Summer 

 and Autumn. — The following is the practice of Mr. Forbes, described in 

 p. 275, 276. of his Hortus Woburnensis, noticed in p. 601. of the present 

 Number. " About the latter end of May, or beginning of June, the plants 

 may be turned out of doors, and placed in a situation where they can have 

 the benefit of the morning and evening sun, but sheltered from the westerly 

 winds, and scorching effects of the sun's rays in the middle of the day; 

 and arranged so as that a free circulation of air can readily pass among the 

 whole collection, which will prevent their being drawn up in a weak or 

 languid state, as is frequently the case when crowded. The scarcer and 

 more delicate-growing sorts should be placed in a pit or frame, where they 

 can also be shaded from the midday sun (by throwing a thin mat over the 

 frame), and protected from heavy rains. If the autumn months are at 

 all favourable, the plants may be left out of doors until the middle or latter 

 end of October, when they should be all cleaned and replaced in the 

 heath-house ; but, if the season is wet, they will require to be taken into 

 the house earlier, in order that they may be protected from the heavy rains, 

 which would saturate the soil about their roots, and be injurious to the 

 plants. When the heaths are taken into the heathery or green-house, they 

 should have as large a portion of air given to them as the house will admit 

 of, both night and day, which should never be excluded, except in frosty 

 or cold and wet weather, when the heathery should be shut up at night, 

 but reopened, if only for a couple of hours, in the middle of the day." 



Mr. Whiddon^ s Mode of cultivating Onions and Asparagus, (p. 323.) — 

 I feel myself called upon to thank Mr. Whiddon for the information ad- 

 dressed to me in his letter (p. 323.), and to remark that, had he, together 

 with the description of his mode of cultivation, informed me philosophically 

 of the reason and principle on which he recommends it, he would have 

 conferred on me a greater favour ; my object being to acquire knowledge 

 grounded on sound principles. The peculiarity of Mr. Whiddon's mode 

 appears to me to consist in excluding atmospheric air and moisture from 

 the roots, by treading the mould hard around the onion plants. I am a 

 young man, and, of course, a young gardener, and may have been wrongly 

 instructed ; but I have been taught to believe that the office of the roots is 

 to absorb food in a fluid or gaseous state from the soil, for the sustenance 

 and nourishment of the plant. Let me ask, does the hard trampling of the 

 soil assist or retard the production of such fluid or gaseous food in the 

 soil ; or does it better enable the root to take it up ? 1 should think, upon 

 philosophical principles, that freely admitting atmospheric influence to the 

 root, by occasionally stirring and loosening the soil with a hoe, would much 

 better answer the purpose. I read in Dr. Lindley's Outlines of the First 

 Principles of Horticulture, that the exclusion of air from the roots will 

 always induce an unhealthy condition in the plant, or even death itself. 

 I)r. Lindley further states that " this may be one of the reasons why stiff 

 tenacious soils are so seldom suited to the purposes of the cultivator ; until 

 their adhesiveness has been destroyed by the addition of other matter," 



