NOTE.—­In the use of silicates of soda and potash one precaution is very necessary—­viz., that you really have a soluble silicate, and not a mere mechanical mixture of ground flint and soda:  this is a very different thing, and one, if it be not carefully guarded against, which will lead to nothing but disappointment.  Again, the silicate may be properly made in the first place, but in a long exposure to the atmosphere the soda attracts carbonic acid, and the soda is liberated, and this has defeated my expectations more than once.  Again, though I consider it desirable to defer the application of it until vegetation has fairly started in the spring, yet, in one instance, I delayed the application of it so long, that there was not moisture to dissolve it until the end of June, and then the wheat began to shoot afresh from the roots and the crop was seriously injured by it:  but this was in an exceedingly dry spring, and might not happen again for many years.

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To the same.

LOW MOOR, 18th December, 1845.

SIR,—­I promised to communicate to you the results of my attempt to grow wheat on the same land year after year, this being the fourth crop of wheat (the fifth white crop) grown in successive years on the same soil, and though I consider the crop an indifferent one, I don’t think the failure ought in any degree to be attributed to the over-cropping, but to the wetness and coldness of the season, as well as other untoward circumstances hereafter to be mentioned.

In a former letter of mine of the 12th October, 1844—­which was published in the “Guardian” a few days after—­I gave an account of the crop of 1844, which was a very good one, being fifty bushels to the acre throughout the field, and as much as fifty-two bushels in the best part of it.  This I considered so satisfactory that I had the field again ploughed up and sowed with wheat on the 9th October, 1844, and it is to the results of this crop that I wish to call your attention.  As remarked in my former letter, the field was subsoil ploughed in the autumn of 1843, and this subsoiling was carried to such a depth that most of the drains in the field were more or less injured by it; and although this did no injury to the crop of 1844, owing to the very dry season, yet when the rain came in the winter of 1844, the want of drainage was found to be very prejudicial, and in the wet places large patches of the young wheat went off altogether, and there was a great deficiency of roots in many parts of the field; the long continuance of frost and after that the ungenial weather which continued so long in the spring (of 1845) were also unfavourable, yet with all these drawbacks the appearance of the plant after the growing weather did come, was very promising, and many of my friends predicted that I should have as good a crop as in 1844.  On the 24th March I applied chemical manure of the same kind as I had done in 1844, at the rate of about