348 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



contains the elements of water, oxygen and hydrogen. In the state of 

 vapor it ministers to the growth and life of plants wliich have the power 

 of absorbing the water thus falling upon tliem. Tlie dew conveys carbonic 

 acid gas and ammonia to plants. In {he i'orm of snow it is liighly benefi- 

 cial to winter wheat and other crops. Tliat a heavy fall of snow will pro- 

 tect and shelter the soil and crop from the destructive effect of any severe 

 cold which may follow, there can exist no doubt; it forms a light porous 

 covering by which the escape of iicat from the soil is prevented; it defends 

 the young shoots from sudden alternations of temperature to which the 

 periodical return of the sun's rays continually exposes them, and when 

 spring approaches, by melting slowly, it allows the tender plant gradually 

 to accustom itself to the milder atmosphere; snow, likewise, contains 

 ammonia and consequently nitrogen. Dew, celebrated througli all times 

 and evei-y known tongue for its sweet influence, presents to our view a 

 beautiful illustration of the agency of water in nature's economy, and 

 exhibits one of those amazing adaptations by which animate and inanimate 

 nature is bound together. The great importance of moisture to vegetation 

 is obvious to all. Water constitutes a very large proportion of all plants, 

 without which they either become stunted in their growth or die. In dry 

 weather when all vegetation seems at a stand, no sooner does a shower of 

 rain fall than an extraordinary growth of every variety of herbage at once 

 succeeds, even on poor soils, where otherwise, no matter how well manured, 

 growth would make very slow progress. The annual quantity of rain that 

 falls in any country is of inferior consideration when compared with that 

 of the general and equable distribution of that quantity throughout the 

 days and months of a year. A great quaiitity at the same titne is more 

 hurtful than beneficial, whereas moderate showers falling upon well pre- 

 pared drained land are great sources of fertility. 



The utility of moisture is particularly remarkable in some respcicts; thus 

 in wet climates cereal crops are found to exhaust the soil far less than in 

 those where little rain falls. Oats injure a soil far more in dry climates 

 than in wet ones. A soil of precisely the same quality will be far more 

 productive in a moist climate than in a dry one; at the same time, mode- 

 rately dry weather is by far the most favorable to a great production of 

 cereals; wheat particularly is much more abundant if rain does not happen 

 to fall when it is about to bloom; and a drizzling rain during warm weather 

 when a crop of wheat or rye is approaclnng to ripeness is certain to mil- 

 dew it. 



OF THE WATER CALCULATED FOR IRRIGATION'. 



Clear spring water, in the state in which it issues from the mountains, 

 possesses the most fertilizing quality, and near its source is far warmer 

 than other waters and not liable to be frozen, and may be used if thought 

 necessary in winter. Spring water may be used longer than foul water 

 because it is not apt to render the grass gritty, therefore I give a decided 

 preference to spring Avater crops. In regard to waters impregnated with 

 iron, they were formerly supposed unfit for the purposes of irrigation; but 

 it is now known that ferruginous waters are friendly to vegetation. I have 

 used waters impregnated with the juices of bog meadows and peat mosses, 



