Queries and Answers. 735 



fig tree as to soil and situation, by Mr. James M'Culloch, gardener to Mrs. 

 Boswell. Thanks were voted, with a copy of the last published part of 

 the Society's Memoirs." This remark is quoted to induce to Mr. Pearson 

 and Mr. M'Culloch the, possibly mutual, benefit and pleasure of each 

 other's correspondence on that interesting subject the culture of figs. 

 What fruit so luscious as a perfectly ripened fig fresh off the tree ! The 

 notice of the thorough thriving of Ficus stipulata under a liberal supply of 

 water, to which we alluded in p. 490., occurs in the present Number, p. 689. 



Art. III. Queries and Answers. 



TECHNICAL Terms in Horticultural Chemistry. — Sir, I wish some of 

 your learned correspondents would insert in the Gardener's Magazine a list 

 of the chemical terms relating to horticulture, which are not to be found 

 in an English dictionary, and with their proper accentuation. Such a con- 

 tribution would be beneficial to those of your readers who, like myself, 

 know little or nothing of the learned languages. I would also ask, What 

 is the simplest test for detecting the oxide of iron in soils and subsoils ? I am 

 of opinion that a clayey subsoil, containing oxide of iron, is one cause of 

 the canker in fruit trees ; and also the cause of what is here termed the 

 cancer in the Scotch pine. I have never seen a blown-down cancered 

 tree of this kind, but what had the greater part of its roots rotten, and 

 which had partly penetrated into such a subsoil. I am, Sir, yours, &c. 

 ■ — Wm. Taylor. Aberdeenshire, July, 1831. 



Uses of the Red Spider. (Vol. VII. p. 218. ; Vol. VIII. p. 499.) — J. D. 

 asks (p. 499 ), " Has not Mr. Godsall confounded two very distinct in- 

 sects," under the name of the red spider ? In my communication (Vol. 

 VII. p. 218.) I stated, " I have heard them" (the crimson velvet insects) 

 " stigmatised as red spiders: " also, "I know not whether this insect be- 

 longs to the genus J'carus or not." I think J. D. might have concluded 

 from the above passages that I ridiculed the idea of confounding them, 

 and, of course, endeavoured not to do so myself; although, in the sentence, 

 " since then I have frequently found the Jj'cari," &c, it should, instead 

 of " ^'cari," have been crimson insect, perhaps, which I almost think was 

 the case in my letter. — Wm. Godsall. Hereford, Sept. 29. 1832. 



What is the Mode of dissolving Caoutchouc {Indian Rubber) in Pyroligr.ous 

 Ether, and where is Pyrolignous Ether to be readily obtained? — Sir, Your 

 correspondent, Mr. Mallet, has (at p. 554.) recommended a varnish of 

 caoutchouc [Indian rubber] dissolved in pyrolignous ether as equally cheap 

 and durable for horticultural purposes ; but he has unhappily omitted to 

 describe, for the information of the less informed, the best mode of effect- 

 ing the solution of the caoutchouc in the ether, the time required to 

 effect it, or the price of the pyrolignous ether, which is not, I believe, 

 to be commonly met with in the druggists' shops, not being yet in suf- 

 ficient demand. By supplying this information he will confer a material 

 obligation on many of your readers, and upon me among the number; 

 and enable many to avail themselves of his advice, who may otherwise be 

 prevented from adopting it. Having occasion to varnish an elastic tube, 

 I prepared a solution of caoutchouc in the essential oil, or spirit, as it is 

 familiarly termed, of turpentine ; but I found the process of solution 

 tedious and troublesome, and, when effected, the liquid proved viscid, and 

 slow in evaporation ; an inconvenience of which I know not how to get 

 rid. Possibly, the solution in the pyrolignous ether, if I knew where to 

 procure it, might be effected with more ease, and be free from the objec- 

 jections to which the terebinthine solution is subject. — Wm. Hamilton, 

 M.D. 15. Oxford Place, Plymouth, Oct. 4. 1832. 



