THE FLORAL WORLD AND GARDEN GUIDE. 365 



As a rule, fire to exclude frost should not be started till it is 

 actually freezing, The object should be just to keep pace with the 

 frost, and not to drive the thermometer up to 55° aud 60°. The 

 highest point at which the thermometer should be kept when the 

 fire is banked up for the night is 42° or 40", or even 38° is a better 

 standard, and which the practical reader will be sure to adopt ; but 

 at 42° no positive injury can be done, and will perhaps be safer for 

 the amateur gardener. 



Eire-heat for the expulsion of damp is also worthy of a remark 

 here, because when it is judiciously applied it adds much to keep the 

 occupants of the house in a healthy condition. As a general rule, 

 once a week will be enough for the purpose, and then there are many 

 fine dry weeks through the winter that would not require it, if only 

 an ordinary amount of care is used in watering. When the fire is 

 lighted for this purpose, the day should be fine, that all ventilators 

 may be opened, so as to admit of a free circulation of air amongst all 

 the plants. 



This now leads me to say something on the subject of air-giving. 

 The subject of air-giving is a point in the management of plant- 

 houses on which definite rules cannot be given for the winter season, 

 so much depends upon the outward elements. It cannot be done in 

 a mechanical sort of a manner, at stated hours in the day, because 

 we must be guided by the state of the weather, and the condition of 

 the plants. But taking the generality of small houses, they do not 

 get air enough ; this is owing to a prevailing notion that the plants 

 do not require it, unless the sun is shining brightly ; but this is a 

 false notion, and fully accounts for what we see in the shape of weak 

 and sickly plants, drawn up to a state approaching to wretchedness, 

 and all for the want of a sufficient quantity of fresh and pure air. 

 To the unitiated, this will be a sufficient explanation of the cause of 

 the flower-stems of primulas being twice the length they ought to 

 be, and why those flowers which should be pink are no colour at all. 

 This will explain, too, the reason of the flowers of early cinerarias 

 and tulips being small and almost colourless. In a word, it will 

 explain the true cause of many losses and disappointments which we 

 in our capacity are obliged to hear of. Sometimes we are asked to 

 condemn a quite different agency for these mishaps, but this we 

 always decline to do, because unintentionally the inquirer lets us 

 into the secret of his management by the inquiries he makes. There- 

 fore, before we take up complaints against seedsmen, we always wish 

 to know how the plants were treated. Air-giving ought to be at- 

 tended to the first thing in the morning, by putting on a little at the 

 top of the house at all times when it is not actually freezing. If it 

 is a mild morning, the same may be done with the bottom ventilators, 

 gradually increasing it till the weather will enable you to judge how 

 much can be given for the day. Endeavour as much as possible to 

 create a circulation through the house early in the day, that the 

 leaves may perform their proper functions in a fresh atmosphere, 

 and that those impurities which they give out during the night may 

 be dispersed. It is essential that, with the stimulus of daylight they 

 should breathe a fresh air, for on it they depend for a certain amount 



