Jmuary 4, 1877. ] 



JOURNAL OF HORTICULTURE AND COTTAGE GARDENEE. 



great extent the best way is to clear them out, clean the house 

 thorongbly, and begin with a fresh stock. — M. 



.JDSSI.a:A GBANDIFLOBA. 

 "We are indebted to Carolina for the plant onr figure represents. 

 It is said to have been introduced in 1812, but appears to have 

 found little favour among cnllivatore. Loudon pajs a poor com- 

 pliment to this family of plants, regarding them as unworthy of 

 the name of Jaseien. JussitBa grandiflora is an aquatic plant. 

 A greenhouse is suitable for its cultivation. Though possess- 

 ing no great beauty it might be included in the collections of 

 those desirous of growing plants of this nature. It may be 

 increased by seed sown as soon as ripe, in pots drained and 

 filled with a compost of loam and sandy peat and placed in 



Fig. 1. — Jaseitpa grandifl< 



•water ; also by division. Where there is no aquarium large 

 hasins or bowls may be substituted, I have sometimes beaten 

 clay firmly in the bottom of ordinary garden pots for some of 

 my aquatic pets, and they have succeeded beyond my expecta- 

 tion. It is to be regretted that there is not more interest taken 

 in the various species of water-loving plants, which when once 

 established require but little attention. — N. 



LATE-KEEPING GEAPES. 



Eaely decaying in many instances would be more correctly 

 ■deecriptive than late keeping as applied to bunches which were 

 intended to hang until March, but decnyed before January. 



A variety of causes may have contributed to the decaying 

 of Grapes, such as too much moisture in the air, too much 

 foliage on the Vines, too many plants in the vineries, too late 

 or insufficient ripening of the fruit, and insufficient tbinning- 

 ont of the berries. These are contributary causes of early 

 decay, and they have all of them been aggravated or intensified 

 by a peculiar incidence of the autumn and winter which has 

 not been sufficiently understood. 



There have been periods during the present autumn when 

 good housewives have been sorely puzzled at the unwonted 

 dampness of their dwellings — the " walls have ran down with 

 vater," the floors and ceilings have been damp, and even the 

 " bedding has felt clammy." Such household complaints 

 must have been very familiar to many gardeners, some of whom 

 have not been able to account for the cause of the " walls 

 sweating," while others — who are " given to thinking " — have 

 understood the matter perfectly. But what has this to do with 

 -Grapes? Much, for Grapes will "swiat," as it is erroneously 



termed, under the same conditions as will walls. But in truth 

 it is not " sweating " at all. The moisture which has puzzled 

 good women did not come out of the walls, nor did that pfr- 

 plexing some men come out of the Grapes. 



The season has been unusually mild and damp, yet occasion- 

 ally a few very cold days have been experienced. These cold 

 days have been followed suddenly by unusual mildness, and 

 it has been on the sudden rising of the temperature after the 

 cold days when the '■ sweating " has occurred. If the surfaces 

 of walls, glass, calico, or Grapes become unusually cold and 

 the temperature surrounding them suddenly rises, the cold 

 surfaces become condensers, and the moisture of the air is 

 transformed by them from the invisible to the visible state. 

 The greater the difference in the temperature of the surfaces 

 end that of the surrounding air, the greater is the quantity of 

 moisture that is precipitated. The moisture does not come 

 out of the walls and the Grapes, but out of the atmosphere. 



That is an important fact to be remembered ; and another 

 equally important is, that the moisture is governed by the 

 temperature. It is not enough that the air of a vinery where 

 Grapes are required to be kept dry should be provided with a 

 steady or a mimimum temperature of 40' or 45°, for if a house 

 has been at 45° for a week, and the outside temperature 

 suddenly rises to 55° (which has more than once been the case 

 lately), moisture will inevitably bo condensed by the cooler 

 surfaces of the Grapes. Wheu the air outside is clear, cool, 

 and dry, as it frequently is iu winter, then there is little or no 

 moisture to precipitate on the Grapes, and a house temperature 

 of 40° is safe ; but when the prevailing outside temperature is 

 high, also moist, then the inside temperature must be high 

 too, or the Grapes cannot be kept diy. 



'J he condensation of moisture is doubtless understood by 

 many gardeners ; a few there are, however, who do not fully 

 appreciate it, and for the sake of these few the matter may 

 well be made plain. Take a cold slate — a common school 

 slate — and cover it with writing on a wintry day; step with it 

 into a heated plant stove, and in less than five minutes the 

 writing will be invisible, the slate having become covered with 

 dew condensed from the warmer atmosphere. Now place the 

 slate on the hot-water pipes and heat its surface, and the 

 writing is again visible, and continues so as long as the slate 

 is kept in the house. That is jast what walls and Grapes do 

 after a week of cold weather being followed by a sudden rise of 

 temperature. Their surfaces do not become warmed so quickly 

 as does the air Burrounding them, and hence the " sweating" 

 — the condensed moisture — causing in one case decay, and In 

 the other discomfort. 



By taking cognisance of the principle of dew-formation, and 

 guiding the temperature accordingly, much may be done in 

 preserving Grapes in a Eeason like the present, but without 

 this knowledge, or without having acted in accordance with it, 

 many Grapes have decayed prematurely. Yet after doing all 

 that was possible the fact still remains that the season has 

 been unfavourable for the sound keeping of Grapes, and it is 

 only fair that all concerned should "know the reason why." — 



A N0BTH£BN QaBDENEB. 



THE PEKSIMMON. 



In your Journal of November HOth in an article on Diospyros 

 Kaki you repeat the popular opinion that the Diospyros vir- 

 giniana's fruit "is not palatable until frozen." Allow me to say 

 that this is a fallacy. The Persimmon, as it is known througti 

 the southern half of the United States, is quite variable in the 

 size, season, and quality of its fruit, and 1 have no doubt will 

 be ultimately developed by selection into a valuable species 

 of fruit. I have seen ripe specimens in this latitude (69* N., 

 about St. Louis) as early as the end of August, whilst the 

 fruit of some trees hardly ripens at all, or if so, imperfectly, 

 by the time cold weather begins. But the ripening and sweet- 

 ness seem to depend entirely on the length and heat of the 

 summer, and not at all on the subduing powers of early 

 frosts. Hot summers produce early-ripened delicious fruit , 

 cold seasons and high latitudes produce poor fruit. Arthur 

 Bryant (a brother of the poet Bryant), living at Princeton, 

 Illinois, about latitude -ill N., tells me that in some seasons 

 the Persimmon with him does not ripen, and he thinks the 

 frost has nothing to do with its maturing. He has trees nearly 

 forty years old of his own planting, and has observed them 

 closely. 



The Persimmon varies also a gocd deal in size. I have 

 heard of specimens 2 inches in diameter, and have teen thtm 



