488 



the affinity of the oxygen of the atmosphere is Jiearly balanced by the 

 weakened, thoug'h not destroyed, vitality. At this stage the beautiful 

 red and yellow tints are developed, which produce so fine an effect in 

 certain kinds of scenery. Then comes more complete death, when the 

 affinity of oxygen acts without any opposition, and the various brown 

 tints of later autumn make their aj^pearance, due to changes which we 

 can imitate in our experiments with dead compounds. 



Hydrated leme on water-plants. — Bauer found small crystals on 

 conferva? in a fresh-water pond, which, on further examination, he dis- 

 covered to consist of a hydrate of the carbonate of lime, containing five 

 molecules of water, precisely similar to those first discovered by Pelouze 

 in a solution of lime in sugar, and subsequently detected in a well-tube. 

 This hydrate is distinguished by the peculiarity of losing its water at 

 a temperature higher than 59° F., even when under water. 



Sub-tropical gardening in England. — One of the most successful 

 attempts at sub-tropical gardening in England is on the estate of Mr. 

 Eobert Were Fox, F. R. S., at Penjerrich, near Falmouth, in Cornwall. 

 The temperature is here extremely mild in winter, the thermometer never 

 falling below the freezing-point for more than two or three nights in 

 succession, and hardly ever below 30° F,, and snow never lying on the 

 ground. Many trees and shrubs which are only seen in hot-houses in 

 other parts of England here grow to perfection out of doors. The 

 hydrangeas, covered with magniticent masses of blue flowers, here form 

 splendid banks by the side of a stream running through the grounds, 

 the small lakes in which are covered with several exotic species of 

 water-lily, and the grass by the side carpeted with the selaginelle, 

 which forms such a favorite bed for ferns in green-houses. Tliere is a 

 specimen of rhododendron 180 feet in circumference, and the camellias 

 are everywhere loaded with fruit. The dragon's-blood tree {Braccena 

 draco) grows Avell out of doors, as also does the Australian gum tree, 

 {Eucalyptus glohulus.) There is a magnificent specimen of the camphor- 

 tree, [Laurus camphora^) and several of the rare Bcnthamia. Several 

 marmosets are allowed free liberty in the grounds, climbing to the tops 

 of the highest trees, and always returning to the house at night. At a 

 spot on Falmouth Harbor called Flushing, the temperature through the 

 year is even still more equable, and the establishment of a tropical 

 garden there would probablj^ be attended with the most successful 

 results. 



The jardin d'essai in Algiers.— The Frencli government estab- 

 lished man}' years ago in Algeria a '*jardin d'essai," in whi(;h all plants 

 likely to be easily grown in Algeria, and which might be useful either for 

 their ornamentation or from their economic value, should be kept for 

 distribution or for sale. The Societe Generale Algerienne has now the 

 control of these gardens, and, under the able management of its present 

 president, M. Anguste Rivero, they have attained great interest and 

 importance. An avenue was planted in 1847, which now consists of 

 about eighty trees of the date-palm, from 20 to 50 feet high, and about 

 one hundred and fifty of the dragon's-blood tree, [Dracoena draco^) about 

 8 feet in height. All the trees were, in last December, in full flower or 

 fruit. Among the more remarkable of the smaller avenues is one formed 

 of bamboo, {Bamhusa arundinacea,) planted in 1SG3, and forming an 

 immense mass of foliage, the stems supporting which are from 40 to 50 

 feet high ; and another formed of about one hundred plants of Chamcvrops 

 excelsa, each being about 10 feet in height; other palms which flourish 



