376 Answers to Queries, and Queries. 



another pipe about 6 in, in diameter, filled with water. The water and 

 steam-pipes surround the house to be heated in the usual manner: they 

 are made gradually to descend from the place where the steam enters to 

 where it escapes, in order that the condensed water produced from the 

 steam may be conveyed back again to supply the boiler. In order to obviate 

 the mischief that might arise from the expansion of the water to be heated, 

 and the consequent generation of steam in the water pipes, a cylindrical 

 vessel, placed on end, and open at top, is connected with the pipes, and in 

 this- the water may rise and fall according to the degree of contraction or 

 expansion to which it may be subjected. It will be evident to whoever 

 compares this plan with the simple and beautiful system in present use 

 (p. 186."), that it is a much more expensive and uncertain mode of effecting 

 the same object. It has, however, the historical merit of forming one step 

 in the progress of this improved mode of heating. — Cond. 



Cotonnier, Virginian Swallow Wort, Asclfyias syriaca. — Sir, Allow me to 

 enquire, through the medium of your Magazine, whether the plant called 

 Cotonnier, cultivated in Lower Canada, has yet been introduced to this 

 country, and, if it has not, to suggest the propriety, of its being imported; 

 for, from the following description, taken from a book of travels, it seems 

 likely to be a useful and ornamental addition to our culinary vegetables: — 



" The cotton plant, Cotonnier, comes up in May, like asparagus, and is 

 dressed and eaten as such in Canada. Its flowers resemble those of lilac. 

 In the month of August, a dew appears on its leaves and flowers, which, 

 .shaken off into basins, about sunrise, and boiled down, yields a good sugar. 

 The stem contains a lactescent liquor; the seed-pods are the shape of an 

 egg, three or four inches long, and contain a fine white silky substance." 



[The plant alluded to is the Jsclepias syriaca, which has been in the 

 country since the time of Parkinson, in 1629. It is common in collections, 

 is of the easiest culture, but neither are the tops used as asparagus, nor the 

 down of the pods for stuffing pillows or beds, as in Virginia.] 



May I also ask where plants of the Norway Cloud Berry, Riibus Chamez- 

 mbrus, so highly spoken of by Dr. Clarke and others for its refreshing and 

 salubrious fruit, is to be obtained ? — A Constant Reader. 



Not about London, but any nurseryman at Edinburgh, or other towns 

 to the north, may be written to, to send up turves containing the plant, 

 which turves are conveniently got from its native habitats in October or 

 March. In this way we have received it ; but we doubt its living for any 

 length of time so near London as Bayswater. — Cond. 



Double Yellow Rose, in answer to R. N. — This rose flowers better on an 

 east or west, or even a north wall, than on one exposed to the south. It 

 should never be pruned farther than cutting out the dead roots or irregular 

 shoots, and thinning out the blossom buds. It has flowered under such 

 treatment for several years on the south and west ends of a small hot-house 

 in the garden at Pain's Hill, and in the garden at Cobham, in Kent ; it flowers 

 as freely, budded on the /26sa indica, as R. odorata does on the common 

 blush rose, which Mr. Calvert of Rouen has found to be the best stock for 

 this variety. — C. Sept. 26. 



Bursting the Double Yellow Rose, in reply to R. N. (p. 119.) — I believe 

 it is very rare for it to open perfectly. I have one against a west wall, and 

 this year I think there must have been nearly, if not quite, a hundred roses 

 on it, but not many that opened fully : those that did were beautiful. I 

 have been told that chamomile plants should be planted at the root of the 

 rose : this I shall try. I have observed that there are often many flies 

 hovering about the tree. Whether they eat the rose, I cannot make out ; 

 but I shall watch next year, and pay particular attention ; and should I 

 make any favourable or useful observations, R. N. shall hear again. The 

 yellow rose will bud on the China rose, and has flowered after this process. 



