ON ROOTS. 



Mrs. B. The only provision which Nature appears 

 to have made with this view, is, to have formed the pores 

 of the spongioles of such small dimensions, that they 

 are incapable of absorbing a liquid which is thick or glu- 

 tinous ; for if the fluid be loaded with particles not ex- 

 tremely minute, they cannot pass through the tubes 

 which compose the vascular system of the plant. I do 

 not mean to say that these pores have any power to re- 

 ject a dense or viscous fluid, but that they will be clogged 

 and obstructed by it, and the absorption consequently 

 cease. 



Water which has flowed through the manure of a farm- 

 yard, and abounds with nutritive particles, is much used 

 on the Continent, for watering gardens ; yet, unless co- 

 piously diluted with pure water, it is found to be delete- 

 rious, choking the plant with an excess of food. But 

 when the liquid is sufficiently limpid, the spongioles suck 

 it up with equal avidity, whether it contains salubrious 

 nourishment or deadly poison. 



Emily. Oh, my poor plants ! Why did not Nature 

 grant them some means of preservation from such dangers? 



Mrs. B. Nature has bountifully diffused throughout 

 the soil such fluids as are adapted for the nourishment of 

 the vegetable creation. No streams of poison flow with- 

 in their reach. It is unnecessary, therefore, to guard 

 against a danger which does not exist. It is merely from 

 the experiments of the chemist and the physiologist that 

 we learn that the roots of plants will absorb liquids, of 

 whatever nature, presented to them, provided they be 

 sufficiently limpid. The spongioles act only by capillary 

 attraction, and suck up moisture just as a lump of sugar 

 absorbs the water into which it is dipped. As a proof of 

 this it has been shown, that if roots, saturated with mois- 

 ture, be transplanted into very dry earth, the latter will 

 absorb the moisture from the roots. 



Emily. If so, why do not the roots continue to absorb 



103. What will be the effect, if the fluid which surrounds the spongi- 

 oles is viscous 1 ? 104. How is it said that manure must be used in or- 

 der to be serviceable to vegetables'? 105. What fluids has Nature 

 furnished for the vegetable creation 1 106. If Nature furnishes those 

 only which are conducive to the nourishment of vegetables, how is it 

 known that they will absorb others which are not 1 107. On 



what principle do the spongioles absorb water 1 ? 108. What is the 

 proof that they act on the principle of capillary attraction 1 ? 



