§09 Reviews. — Liehig^s Organic Chemistry. 



water beyond all doubt. It has hitherto escaped observation, be- 

 cause no person thouj^ht of searching for it. All the rain-water 

 employed in this inquiry was collected six hundred paces southwest 

 of Giessen, whilst the wind was blowing in the direction of the town. 

 When several hundred pounds of it were distilled in a copper still, 

 and the first two or three pounds evaporated with the addition of 

 a little muriatic acid, a very distinct crystallization of sal-ammoniac 

 was obtained: the crystals had always a brown or yellow color. 



Ammonia may likewise be always detected in snow water. Crys- 

 tals of sal-ammoniac were obtained b}' evaporating in a vessel with 

 muriatic acid several pounds of snow, which were gathered from 

 the surface of the ground in March, when the snow had a depth of 

 ten inches. Ammonia was set free from these crystals by the addi- 

 tion of hydrate of lime. The inferior layers of snow, which rested 

 upon the ground, contained a quantity decidedly greater than those 

 which formed the surface. 



It is worthy of observation, that the ammonia contained in rain and 

 snow water, possessed an offensive smell of perspiration and animal 

 excrements, — a fact which leaves no doubt respecting its origin. 



Thus the old homely adage, that the late snows of spring 

 are the poor man's manure, may have had more meaning than 

 we had " dreamed in our philosophy," and seems to have 

 been based on strictly scientific truths. 



The facility with which plants take up foreign substances 

 into their systems, was exhibited by Marcet, in producing 

 their death by means of mineral poisons, but we find a more 

 innocent and amusing experiment in the following, which we 

 quote as a matter of mere curiosity; — 



When the soil, in which a white hyacinth is growing in the state 

 of blossom, is sprinkled with the juice of the Fhytolaca decandra, 

 the white blossoms assume, in one or two hours, a red color, which 

 again disappears after a few days under the influence of sunshine, 

 and they become white and colorless as before. The juice in this 

 case evidently enters into all parts of the plant, without being at all 

 changed in its chemical nature, or without its presence being appa- 

 rently either necessary or injurious. But this condition is not per- 

 manent, and when the blossoms have become again colorless, none 

 of the coloring matter remains; and if it should occur, that any of its 

 eletnents were adapted for the ])urposes of nutrition of the plant, 

 then these alone would be retained, whilst the rest would be excreted 

 in an altered form by the roots. 



The presence of the alkalies in natural soils, imparting 

 thereby, according to their quantity, a })roportionate fertility, 

 is thus made the basis of a deduction regarding the native 

 growth of forests on diflerent lands. This, we presume, 



