Retrospective Criticism. 241 



at all uncommon to find different men simultaneously discovering the same 

 physical facts ; and we are not sure but Mr. Shirreff of Mungoswells, East 

 Lothian, a scientific farmer, might also claim kindred with this popular bant- 

 ling ; for it is several years since he recorded the same opinions, in an essay 

 on " The gregarious nature of grasses." [See Quart. Jour, of Agric., vol. ii. 

 p. 242.] Gardeners, of all others, have an excellent opportunity of investi- 

 gating this theory ; and we recommend this and similar articles to their serious 

 attention. (G. in the Dundee, Perth, and Cupar Advertiser, March 14. 1834.) 



Directions for dissolving Indian Rubber by Means of Pyroligneous Ether. 

 [IX. 243.] — When a work is put forth in the style which distinguishes the 

 Encyclopaedia of Gardening, it is but reasonable to expect correctness at least 

 in the information it professes to afford, beyond all other publications. A 

 specimen of that correctness may be found in the Number for April, 1833, 

 which contains directions for dissolving Indian rubber by means of pyroligneous 

 ether. Had you known any thing of the matter, you must be aware that 

 " pyroligneous ether" will not act upon caoutchouc in any way. What was 

 the solvent you might intend under that name is not to be divined. — Anon. 

 with the Hereford postmark, Feb. 17. 1834. 



[We sent this letter to Mr. Mallet, and have received the following reply.] 



I have returned the anonymous note which you sent me. Although ad- 

 dressed to you, I am alone responsible for the charge which it contains. This 

 note is full of mistakes. The writer first mistakes you, the conductor of the 

 Magazine, for the author of my notice respecting the solution of Indian 

 rubber; secondly, he mistakes the Encyclopaedia of Gardening for the Gar- 

 dener's Magazine ; thirdly, he mistakes the number in which the article in 

 question occurs ; and, lastly, he mistakes in the general assertion of his note, 

 viz. " that pyroligneous ether will not act upon Indian rubber in any way." 

 As this is a simple assertion of fact, it does not admit of argument : I, therefore, 

 only say, if the author of the note remains incredulous on the subject, and 

 will venture to come forward, I will send } 7 ou some of the solution for his in- 

 spection. A word or two more may possibly enlighten him as to the origin of 

 his mistake. The fluid to which the name of pyroligneous ether is applied, 

 differs much in its properties, as obtained from different manufactories : some 

 of it will dissolve Indian rubber, and some of it will not. For the truth of 

 this he may have the authority of Berzelius : — " Les contradictions que pre- 

 sentent ces donnees sur des experiences aussi simples, paroissent indiquer 

 qu'il existe plusieurs especes d'esprits pyroligneux qui ont de l'analogie sous 

 certains rapports, mais different les uns des autres par quelques-unes de leurs 

 proprietes." {Traite, &c, torn. vi. p. 674.) I confess myself to blame in 

 not having noticed this in my former observations upon this menstruum. 

 However, since I made that communication, I have found that there is no 

 solvent of Indian rubber so good for gardening and most other purposes, as 

 refined coal tar, sold under that name by drug merchants, which is only com- 

 mon coal tar deprived of water by boiling. — Robert Mallet. 24. Capel Street, 

 Dublin, March 19. 1834. 



Mr. Munro's Suggestion (p. 551.) for the Formation of a Sylvan Society 

 I am much pleased with,.and I agree with him in almost all he says on the 

 subject. I seldom pass by other people's woods or plantations but my fingers 

 itch to thin, and weed, and prune out. In short, as Mr. Munro has truly 

 said, " the greater proportion of our woods, from neglect or mismanagement, 

 look as if they belonged to nobody." — W. T. Bree. Allesley Rectory, near 

 Coventry, Warwickshire, Oct. 19. 1833. 



The Oak Trees which turn away their Heads from the South-west (p. 548.), 

 described by Mr. Clarke, are by no means peculiar to his part of the country 

 [Poole, Dorsetshire]. Years ago, I was much struck with the same thing in 

 the Isle of Wight, and have often said, that, were I ignorant of the points of 

 the compass, I could immediately discover them by looking at an oak tree. 

 Even in Warwickshire, in exposed situations, the oak trees show their aversion 

 to the south-west, by turning away their heads from that quarter. — Id. 



Vol.X. — No. 50. R 



