376 Queries atid Ansrvers. 



men desirous of improvement. I am, Sir, yours, &c. — Richard Patersoii, 

 Gardener to F. W. Campbell, Esq. Birlcfield Lodge, near Ipswich, Feb, 15. 

 1833. 



A Society at Guernsey for purchasing and circidating Books on the Art and 

 Science of Horticidture . — A few months back, some amateur gardeners here, 

 to promote their mutual amusement and instruction, formed themselves into 

 a society for purchasing, and circulating among the members, books on 

 the art and science of horticulture ; and each member thereby obtains, for 

 a small annual subscription, the perusal of a considerable number of books. 

 Might not this plan be generally recommended to young gardeners, both 

 amateur and professional, to their advantage ? — A Member of the Guernsey 

 Horticultural Book Society. 



Ten shillings and sixpence was the charge of the annual subscription to 

 . a mechanics' institute to which I once belonged (at Bury St. Edmunds, 

 Suffolk) : the advantages this sum procured were, the use of numerous 

 volumes, and the hearing of occasional lectures on different subjects in 

 science. The Ipswich Mechanics' Institute, of which Mr. Paterson is a 

 distinguished member, is numerously supported ; and rich in books and 

 apparatus, and specimens of various objects ; and lectures, and able ones 

 too, are delivered at it, to the amount of twenty-two in a year, by volun- 

 teers among the members. I recollect seeing, in a last year's Ipswich news- 

 paper, a report of an able lecture on the practice of pruning fruit trees, 

 delivered by Mr. Paterson himself: the principles he recommended were 

 chiefly those of Hayward. By a list of the lectures for the present year 

 a friend has sent me, it appears that Mr. Paterson stands engaged to give 

 one " on horticulture," on Oct. 28. Mr. Woollard, too, is to give one on 

 the " history of horticulture," on March 18. Among the remaining lec- 

 tures, there are two to be given on "natural history," by Wm.Batley, 

 Esq. ; and one on " botany," by Mr. Webster. — ,/. I). March 8. 1833. 



Tests for detecting Oxide of Iron in Soils and Subsoils. — Sir, To your 

 correspondent's enquiry, " What is the simplest test for detecting the 

 oxide of iron in soils and subsoils ? " I beg to say, that I think the enquiry 

 he wishes to make is, how can you most easily determine the proportion of 

 oxide of iron existing in soils ; for, as to merely detecting the existence of 

 oxide of iron, there is, perhaps, not a soil or subsoil from John-o'-Groat's 

 House to Lizard Point that does not contain it. For Mr. Taylor's pur- 

 pose, it wDl be sufficient if he can determine pretty nearly the amount of 

 metallic oxides in the soil he examines. For this purpose, let the soil be 

 dissolved in diluted muriatic acid ; or, if insoluble, fused previously with 

 excess of carbonate of potass, and then dissolved. Solution of ferro- 

 cyanate of potass (or prussiate of potash of the druggists) will precipitate 

 all the metals usually found in soils : and, if iron predominate, the preci- 

 pitate will be blue ; or white, if the iron is in a low state of oxidisement, 

 but becoming blue on exposure to the air. If this precipitate be heated red 

 hot, it will be decomposed, and the result will be the oxides contained in 

 the soil. Mr. Taylor will, I am sure, not be offended when I say that the 

 separation of these metallic oxides individually, either from the soil or from 

 one another, requires more skill and manipulation than any one not 

 versed in chemical operations is likely to possess ; for which reason I have 

 confined myself to giving the foregoing simple (and, to a chemist, clumsy) 

 mode of answering Mr. Taylor's question. I believe it is generally con- 

 ceived that canker is caused by the roots of trees so affected getting into the 

 subsoil ; and I believe Mr. Taylor is quite right in supposing that the oxide 

 of iron is the cause of it : but not immediately, as it appears to me the 

 proximate cause is the total want of minutely divided and decayed vege- 

 table matter which is found in such subsoils. Certain it is that trees will 

 thrive well in soils that contain an enormous quantity of iron, provided 



