282 



FOREIGN NOTICES. 



3. Ipoincea horsfallite , a splendid plant, with deep- 

 ly lobed leaves, and bunches of crimson blossoms ; 

 should have a warm close position. 4. Mandevilla 

 suavcolens, a very free grower, with hairy oval 

 leaves, and bunches of white deliciously fragrant 

 flowers. 5. Passifloraracemosa, a splendid crim- 

 son passion flower, which will flower freely nearly 

 the whole year ; does best grafted upon one of the 

 hardier sorts. 6. Plumbago capensis, an easily 

 grown plant, with long slender stems, bluntish 

 leaves, and good sized bunches of pale blue flowers; 

 may be had in bloom from April to November, by 

 cutting back some of the strongest shoots in sum- 

 mer. 7. Stephanotis floribunda, a beautiful ever- 

 green plant, with dark green, shining, blunt oval 

 leaves, and bunches of white deliciously scented 

 blossoms ; it is a splendid thing when planted out 

 in a conservatory border, and grows very fast. 

 8. Tecoma jasminoides, a very free flowerer upon 

 the young wood from July to the end of October ; 

 it has much divided leaves, and bunches of white 

 flowers, with a crimson centre. — London Hort. 



Mag. 



Manure- WATER for Pot Plants. — Many — in- 

 deed most — plants grown in pots may, at particu- 

 lar periods of the growth, be advantageously treat- 

 ed with liquid manure ; these periods are chiefly 

 during the time of making vigorous growth, and of 

 blooming. Inexperienced persons, however, are 

 liable to do material injury from using it too strong 

 or too often ; or they fall into the other extreme, 

 and derive no benefit from the application. A very 

 useful liquid manure for pot plants may be made by 

 putting the following ingredients into a hogshead 

 of rain water : — two pecks of sheep or deer dung, 

 one peck of soot, and two quarts of Potter's guano; 

 these ingredients are first to be well mixed up to 

 the consistence of paste, with boiling water, and 

 then mixed with cold water. Stir the mixture fre- 

 quently for a day or two, and then throw in a quart 

 of quicklime ; when the liquid has become clear it 

 is fit for use. For all strong growing plants this 

 may be used daily, or every other day — applying it 

 diluted with about one-third of clear water. For 

 heaths, and similar delicate rooted plants, and even 

 for orchids, it will prove beneficial, but to these 

 should not be given oftener than once a week. As 

 before observed, it is only to be used — at least by 

 the inexperienced — during the periods of growth 

 and blooming — Lond. Hart. Mag. 



Colored Glass for Hot-houses. — It has been 

 found that plants growing in stove houses often 

 sufi'er from the scorching influence of the solar rays, 

 and great expense is frequently incurred in fixing 

 blinds to cut oS" this destructive calorific influence. 

 From the enormous size of the new Palm-house at 

 Kew, it would be almost impracticable to adopt 

 any system of shades which should be effective — 

 this building being 363 feet in length, 100 feet wide, 

 and 63 feet high. It was therefore thought desira- 

 ble to ascertain if it would be possible to cut o9" 

 these scorching rays by the use of a tinted glass, 

 which should not be objectionable in its appearance, 

 and the question was, at the recommendation of 

 Sir William Hooker and Dr. Lindley, submitted by 

 the Commissioners of Weeds, &,c., to Mr. Hunt. 



The object was to select a glass which should not 

 permit those heat rays, which are the most active 

 in scorchinor the leaves of plants to permeate it. 

 By a series of experiments made with the colored 

 juices of the Palms themselves, it was ascertained 

 that the rayswliich destroyed their colour, belonged 

 to a class situated at that end of the prismatic 

 spectrum which exhibited the utmost calorific pow- 

 er, and just beyond the limits of the visible red ray. 

 A number of specimens of glass, variously manu- 

 factured, were submitted to examination, and it 

 was at length ascertained that glass tinted green, 

 apjieared likely to effect the object most readily. 

 Some of the green glasses which were examined, 

 obstructed nearly all the heat rays ; but tliis was 

 not desired, and from their dark colour, these were 

 objectionable, as stopping the passage of a consi- 

 derable quantity of light, which was essential to 

 the healthful growth of the plants. Many speci- 

 mens were manulactured purposely for the experi- 

 ments by Messrs. Chance of Birmingham, accord- 

 ing to given directions, and it is mainly due to the 

 interest taken by these gentlemen that the deside- 

 ratum has been arrived at. Every sample of glass 

 was submitted to three distinct sets of experiments. 

 1st. To ascertain by measuring ofT the coloured rays 

 of tlie spectrum, its transparency to luminous in- 

 fluence. 2d. To ascertain the amount of obstruc- 

 tion oflfered to the passage of the chemical rays. 

 3d. To measure the amount of heat radiation which 

 permeated each specimen. The chemical changes 

 were tried upon chloride of silver, and on papers 

 stained with the green coloring matter of the leaves 

 of the Palms themselves. The calorific influence 

 was ascertained by a method employed by Sir John 

 Herschel, in his experiments on solar radiation. 

 Tissue paper stretched on a frame, was smoked on 

 one side by holding it over a smoky flame, and then 

 while the spectrum was thrown upon it, tlie other 

 surface was washed with strong sulphuric ether. 

 By tlie evaporation of the ether, the points of calo- 

 rific action were most easily obtained . as these dried 

 off in well defined circles long before the other 

 parts presented any appearance of dryness. By 

 these means it was not difficult, with care, to as- 

 certain exactly the conditions of the glass, as to its 

 transparency to light, heat, and chemical agency 

 (actinism.) The glass thus chosen is of a very 

 pale yellow green colour, the colour being given by 

 oxide of copper, and is so transparent that scarce- 

 ly ani' light is intercepted. In examining the spec- 

 tral rays through it, it is found that the yellow is 

 slightly diminished in intensity, and that the ex- 

 tent of the red ray is affected in a small degree, 

 the lower edge of the ordinary red ray being out oflf 

 by it. It does not appear to act in any way upon 

 the chemical principle, as spectral impressions ob- 

 tained upon chloride of silver are the same in ex- 

 tent and character as those procured by the action 

 of the rays which have passed ordinary white glass. 

 This glass has, however, a very remarkable ac- 

 tion upon the non-luminous heat-rays, the least re- 

 frangible calorific rays. It prevents the permeation 

 of all that class of heat raj's which exist below and 

 in the point fixed by Sir William Herschel, Sir H. 

 Englefield, and Sir J. Herschel, as the point of 

 maximum calorific action. As it is to this class of 



