Litchfield enquirer., 1854-01-26
Br DR. HUoAo.

Water followed from the ocean to she Ocean
 Conveyance of carbon to plants.
 5 Conveyance of oxygen to plants.
 Conveyance of hydrogen 10 plants. Conveyance of nitrogen to plants.
 The inorganic constiluent of plants.
 / Changes and course of sap within the plant
 3 Water carrier of plants and seeds.
 HI. Let us now consider water as . carrier in the vegetable world
 The constitution of vegetables and the chemical phenomena of vegetation must be briefly considered. in order to appreciate the offices which water per- forms in the perfection and decomposition of plants. Vegetables are composed oi carbon. hydrogen. oxygen and nitrogen ]: lime. soda. potash. magnesia, alumnia, silex, sulphur, phosphorus. manganese and iron occur in variable proportions.
 The seed of d plant consists of germ and two seed lobes. both of which are contained in the same enclosure. The germ consists of the radicle, which de- scends into the earth during germination, and the plumulc, which rises and niii. mately forms the trunk of the plant. - The seed lobes contain noutishing matter, with which, through the medium of air and water, they supply the plant till il can itself draw materials f,om the earth and air. The trunk of the tree or plant is composed of system of tubes rising upward though the wood. called cons mon vessels. These correspond to the pulmonary arteries of animals. and are sab-dwided and distributed among the leaves or lungs. Through the inner layer of the bark runs another system of tubes. called proper vessels. which correspond with the other arteries of animals.
 The sap, like blood, is water holding various substances in solution.
 The roots are b.divided like the branches. and project from the tree into the earth in all directions. The ends of the roots are more tender than the other portions, and terminate in q soft spongy substance by which the various gases ard liquids are imbibed.
 ? Having now considered the varions properties which may aid water in the capacity of carrier, and having noticed the general structure of plants, let us follow portion of water from the oaean to tho ocean, and observe the manner and extent of its operations as carrier.
 A portion of sea water is by the suns heat evaporated, together with minute portions of the matter it holds in solution. Passing up through and constituting a portion of the atmosphere. the larger part of this watery vapor is. by the ab- sence of caloric. condensed and rendered visible. when by the force of the winds and in some circumstances by he attrac- ton of mountains, 1t Is carried above the land. A still greater reduction of heat causes the water to be precipitated iu the form of rain. This absorbs portions of ,he gases of which the atmosphere ia composed. VIE: oxygen, hydrogen, car. bonic acid gas and nitrogen. The carbon. as will be shown under another head. is of great use 10 the water in dissolying solid substances, such as carbonate of lime.
 Rain water is further impregnated with animaculaes ard their germs, and with dust containing ear.hy and alkaline mat- tcrs. which the wind carries up from the earth 1: and if the rain is encountered by winds containing sea spray, saline matt ters will also be mingled with t. It also contains the carbonate Of ammonia. in . gaseous slate, which has been eliminated from decaying organic mstter.
 Thus. rain water operates as . carrier in the formation of soils, by facilitating the decomposition of rocks, &c. Let us for the presen. suppose the soil 10 be formed and to contain the requisite orr ganic and inorganic matters tor the nour- ishment of plants. M
 Starch. sugar and gum, when accom- panied by any sabslaace containing nj. irogen. serve to sustain the embryo. uniil ils organs are sufficiently developed to feed exclusively sn carbonlc acid. wa'er. and ammonia. Water. in some manner, which is yet imperlectly understood. aids in conveying and sssimulasisg the food ol young plants. Tho roots of older plants possess duiing life. the power of absorb ing water through their spongy extrem- etics. and with t. carbonic acid and air. Some chemists allifm Ghat pure wateS and air alone will support vegetable life. in which ease water is carrier of its own elements. But water once impreg> naied, cannot be made absolutely pure. hence Il is carrier of solid substances in ell eases. 5's rs H*i
 q Tho original source of ths ea,bnn which plnnls have AssimuiAssd. was she atmosphere. and t is undoubtedly the main source 0g iis present supply. When carbon exisla to ths soII, snsalf portions of ii ase supposed sa esisT the roots ol plants in sks form of eaShonis aeid dln- solved in watas. CeFinim compounds oi enrbon and wnisF saIlsd huelic aeid. Al. mis Asla. and asls aeld. dsslevd pslnpl. Al aR0 A T. 4ss E A -oA