Queries and Answers. 395 



take place from either side at the outlets, without showing the real course 

 of the sap in the perfect vessels. 



I am much pleased that Pi'ofessor Henslow has noticed Mr. Niven's paper ; 

 and especially as the results of the experiments of the latter are corroborated 

 by the comparisons of the former gentleman. Mr. Niven's facts may receive 

 much valuable elucidation from the talents and pure science of the professor. 

 Already it is acknowledged that the life of a tree has " a local habitation," if 

 it has not yet received a scientific name ; and, if it be admitted that a protu- 

 berant margin of wood and bark is often formed round the stump of a felled 

 tree, without assistance from either leaves or descending sap, the time may 

 soon arrive when we shall hear no more of " organisable " fluids, " adven- 

 titious buds," or " equivocal generation," of wood, &c. ; nor shall we be 

 amazed by assertions that the complicated structure of plants may be formed 

 of invisible, though " ponderable," gases ! 



Whatever may be hereafter elicited by the scientific attainments of Professor 

 Henslow, and by the high practical knowledge of the curator of the Glasnevin 

 Botanic Garden, in this branch of vegetable science (though corrective, as, 

 probably, their united discoveries will be of several old points of botanical 

 physiology), their stations and personal respectability will be a sanction to 

 whatever they may publish, or, at least, will secure them from the odium of 

 " obscurity." — J. Main. Chelsea, May 10. 1838. 



Rhubarb Jelly. (Vol. XIII. p. 460.) — Mr. James M'Nab may have had the 

 merit of introducing this jelly into Scotland ; but the gentleman at whose 

 suggestion it was first made is Joseph Johnson, Esq., of Northenden, near 

 Altringham, Cheshire. Mr. Johnson, in the year 1834, having an unusual 

 quantity of rhubarb stalks, suggested the idea to his daughter, Miss Johnson, 

 of trying how they would make into jelly. The success was complete. In 

 1836, Mr Johnson mentioned this jelly to Mr. Campbell, the curator of the 

 Botanic Garden, Manchester, and sent him a jar of it. Mr. Campbell 

 mentioned the circumstance to Mr. M'Nab, who was on a visit at the 

 Manchester Gardens ; and this, it is presumed, led to Mr. M'Nab's making 

 some when he returned home. — J. J. Manchester, June 10. 1838. 



Art. V. Queries and Ansivers. 



The Effect of Gas Tar on the Stems of Trees. — Can you tell me whether 

 gas tar, or some such substance, applied to the stems of trees, in order to pre- 

 vent horses and cattle biting the bark, would be injurious to their growth ? 

 Paint, I conceive, would be, if applied to any extent. I have been sorely 

 annoyed by a tenant's horse barking some thriving young trees, which I 

 planted in hedgerows twenty years since, and have nursed with great care, 

 and thought they were now safe from all harm. Horses that take to this evil 

 habit, I am told, never leave it. — W. July 19. 1838. 



Art. VI. The London Horticultural Society and Garden. 



April VI. \S3S. — Read. An Account of the Vineyard at Blackheath, in 

 the Seventeenth Century, communicated by Sir Henry Bunbury. 



Exhibited. Azalea Smithi'i coccinea pulcherrima, Hovea Ge\si, Meli- 

 anthus major, Cjtisus sp., from Mr. William Upright, gardener to G. C. 

 Ridge, Esq., of Morden, Surrey. Euphorbia splendens, 6'actus speciosa. 

 Azalea indica alba, A. i. pulchra, seedling cinerarias, seedling calceolarias, 

 from Mr. Green, gardener to Sir Edmund Antrobus, Bart. Cucumbers, 

 from Mr. Patrick Flannagan. Sweetwater grapes, from M. Nieman, gar- 

 dener to Peter Caesar Labouchere, Esq., F.H.S. Gesnera Suttonw, from 

 Messrs. Brown of Slough. Seedling camellia, from John AUnutt, Esq. 

 Cucumber, from Mr. William Curtis, gardener to John AUnutt, Esq. Seed- 



