ON PLANTS. 131 



you may frequently have discovered by the offensive efflu- 

 via exhaled by ponds and marshes of this description ; 

 but the corrupted waters, disgusting and deleterious as 

 they are to us, afford a feast of abundance to the vegeta- 

 ble creation. Saturated with the decayed remnants of 

 both animal and vegetable matter, and replete with car- 

 bonic acid, they convey these rich materials for fresh veg- 

 etation into the roots of the living plant. 



Caroline. The only danger, then, is lest the fluid be 

 too abundantly laden with food, and the plant be gorged 

 with it. 



Mrs. B. As plants are not capable of acquiring the 

 virtue of temperance, Nature has wisely provided against 

 their suffering from excess, by giving them mouths of such 

 very small dimensions, that they cannot take in more than 

 is good for them. The only danger, therefore, is, lest the 

 fluid should be too dense to obtain entrance at the roots. 



The water least appropriate to plants is that of springs ; 

 and, when obliged to use it, we should endeavor to rem- 

 edy the double defect of a deficiency both of air and of 

 temperature, by leaving it exposed during some length of 

 time to the atmosphere. If the reservoir in which it is 

 contained be situated in the neighborhood of a farm-yard 

 or stables, the water will become impregnated with car- 

 bonic acid evolved by the manure. Advantage may also 

 be taken of such a vicinity to enrich the water of the res- 

 ervoir, by conveying a small stream through the manure 

 into it. 



Emily. But spring water is not always of a lower tem- 

 perature than the atmosphere : during a frost it is evi- 

 dently warmer, being sheltered from the cold by the depth 

 whence it rises. 



Mrs. B. Plants do not then require water: it is in 

 summer that this artificial aid is wanted, and never at a 

 season when the temperature of spring-water is higher 

 than that of the atmosphere. 



Emily. One cannot sufficiently admire the beautiful 

 provision which Nature has made for watering her vegeta- 

 ble creation. The rain, falling in small drops through 



730. Why does Mrs. B. say the water of ponds is good for plants'! 

 731. What is the only danger to plants arising from the water by which 

 they are nourished 1 732. What water is least appropriate to plants'? 

 733. What will be the effect upon water if in a reservoir situated near a 

 farm yard! 734. At what periods do plants require water! 



