182 Queries and Answers. 



please, excite some. Mr. Gordon, in his highly ingenious paper, in the Ma- 

 gazine of Natural History, V. 121., remarks that plants, as well as animals, 

 have the faculty of preserving a certain degree of temperature, be that of the 

 medium in which they are placed what it may. " For instance," he remarks 

 that " t the temperature of the. interior of the stem of a tree will seldom sink 

 below 56°, although that of the atmosphere be not higher than 20°." Mr. 

 Gordon imputes this effect, " in a great measure, to various chemical processes 

 going on within their different organs ; yet," he remarks, " it is very clear 

 that it must arise also from other causes ; for it continues to be generated, 

 though in a less degree, even in winter, when every chemical action within the 

 plant is almost entirely suspended." On this curious subject I regret that I 

 have no information to communicate ; it is information I seek ; and, to the 

 end of obtaining it, I would, with your permission, place under Mr. Gordon's 

 observation the following extract from Jameson's Philosophical Journal for 

 June, 1828, p. 204. : — " Schutzer and Haider inserted thermometers into the 

 stems of trees, so deep that the bulb reached the centre of the tree. The 

 same was done into a dead stem. From the results of these experiments, 

 vegetables appear to retain a certain medium temperature, which cannot, how- 

 ever, be considered as originating from heat evolved by the functions of the 

 plant, as the dead stem afforded the same temperature as the living ; but can 

 be satisfactorily explained by a reference to the bad conducting power of the 

 vegetable fibre and the wood, by which the temperature of the surrounding 

 aerial strata penetrates but slowly into the interior of the plant." To the 

 identity of temperature in the quick and the dead, I have one empirical fact 

 to oppose, taught me some years since by a nurseryman of much arboricul- 

 tural experience, the excellent Mr. Samuel Curtis of the Glazenwood Nursery. 

 It is, that a dead branch is invariably warmer than a live one ; and that the 

 difference is, to a practised hand, so perceptible, that he would (in summer 

 only, I believe, though) engage to pass blindfold through the branches of a 

 tree, and distinguish, by the difference in temperature alone, every dead 

 branch from the living ones. He instanced this to me at the time by several 

 examples ; and I really imagined I could perceive a difference. " It stands to 

 reason," he remarked, " that a bundle of tubes, as in the living branch, 

 through which watery juices are perpetually circulating, should be cooler than 

 a dead branch, in which the tubes are all destitute of watery juices." — An 

 Asker. May, 1832. 



Destroying Insects by Decoctions of Cliamomile Floiuers. — In the Irish Gar- 

 dener's Magazine it is said, not only that decoctions, or the leaves dried and 

 powdered, of the common chamomile (J'nthemis nobilis) will destroy insects, 

 but that " nothing contributes so much to the health of a garden as a number 

 of chamomile plants dispersed through it. No green-house or hot-house should 

 be without chamomile in a green or in a dried state ; either the stalks or flowers 

 will answer. It is a singular fact, that if a plant is drooping and apparently 

 dying, in nine cases out of ten, it will recover, if you place a plant of chamo- 

 mile near it." Have any of your readers tried the chamomile in any way as a 

 remedy for insects in England ? — John Brown. Westerham, Kent, Feb. 1834. 



The relative Degrees of Effect on Vegetation of several Sorts of Manure. 

 (IX. 628.) — In making a few remarks, in the way of answers to these 

 queries, I shall arrange the manures included in the list referred to according 

 as they appear to me to deserve precedence by their effects on vegetation, 

 placing the most powerful or active first, and confining my remarks to those 

 sorts of which experience enables me to speak with some degree of con- 

 fidence. 



1. " Night Soil not dry." This, although the most disgusting of the ordi- 

 nary manures, is, perhaps, the most powerful. It is not only active, but more 

 permanent in its effects than some others of the active manures. When de- 

 siccated, or rendered dry, it is less powerful in its active qualities; these being 

 partly neutralised by the lime used in drying it. In this shape, however, it is 

 less repulsive in its application, and as permanent in its effects. 



