The Arizona champion., 1890-10-11
TREES SANITARY INFLUENCE.
Their Relation to Dwelling Houses and
 to Individual Health.


 to Individual Health.
 For the last few years public attention has been quite frequently called to the influence of trees upon climate. The special issue of the United States agricul- tural department on forestry, and many other contributions, have shown how rainfall is affected, how the balance of the atmosphere is disturbed and how climate changes from the extended and rapid removal of forests. There is an- other study of trees allied to this which has reference to their relation to houses and to individual health.
 Both the atmosphere and the soil are cooled and moistened by the presence of trees. This results from the drawing up of the water from the subsoil and from the exclusion of the suns rays. Besides this, considerable portion of the rain- fall collects on the leaves and branches. M. Fantiat has shown ''that the leafage of leaf-bearing trees intercepts one-third and that of pine trees one-half of the rainfall, which is afterward returned to the atmosphere by evaporation. On the other hand, these same leaves and branches restrain the evaporation of the water which reaches the ground. This evaporation is nearly four times less under mass of foliage in forest, and 1-3 times under mass of pines, than in the open" Then we have stagnation of air from that interruption of wind currents caused by the foliage.
 It is, therefore, not without reason that the sanitarian studies the trees of the yard or lawn in their bearing upon individual health. Persons of suscepti- ble lungs, or having any tendency to rheumatism, need to be carefully guarded against such influences. Where the foli- age is dense about houses, or where the limbs overshadow the piazzas or roof, they become the storage places for damp, unwholesome air. The falling leaves gathering from year to year give a cor responding dampness to the soil, while at time of foliage the sunshine is measura- bly excluded. It is pretty evident that mankind was not intended to be reared in the woods. The influence of trees in causing malaria, or in so intercepting it as to have it tarry among them, has long been known. "A dry garden on gravel of three acres in extent in Surrey, sur rounded by trees, is generally three or six degrees colder than the open com mon beyond the trees, and large pond in pine wood twenty miles from Lon don afforded skating for ninety consecu- tive days in the winter of 18S5-6, while during the greater part of the time the lakes in the London parks were free from ice"
 We know with what interest the lover of trees watches the growth of those planted by his own hand, and how many are apt to be scattered about the new home mansion. As years go on, and their growth and foliage increase, the | owner is 10th to remove them or severely to shorten their branches. If so, there is great danger that the dry soil and once comfortable home will come to be the dampest and least desirable spot in the neighborhood. A recent careful writer has given the following sensible direction as to tree planting as it bears upon the conditions of health: "A tree should not stand so near house that if it were to fall it would fall upon the house, or, in other words, the trunk should be as far from the house as the height of the tree. Belts of trees may be planted on the north and east aspects of houses, but on the east side the trees should not be so near nor so high as to keep the morning sun from the bedroom windows ill the shorter days of the year. On the south and west aspects of houses, isolated trees only should be permitted, so that there may be free access of the sunshine and of the west winds to the house and grounds. High wall and palings on these aspects are also objectionable, and should be re- placed by fences, or, better still, by open palings, especially if the houses are oc- cupied during the fall of the leaf and ill | the winter.
 "Trees for planting should be chosen in the following order: Conifers, birch, acacia, beech, oak, elm, lime and poplar. For our American homes we must add the maple, the ash and the tulip tree, or American poplar, although the dense foliage of the maple is sometimes ob- jectionable. Pine trees collect the greatest amount of rainfall and permit the freest evaporation from the ground, while their branchless stems offer the least degree of resistance to the lateral circulation of the air. Acacias, oaks and birches are late to burst into leaf, and therefore allow the ground to be warmed by the sun S rays ill the early spring. The elm, lime and chestnut are the least de- sirable kind of trees to plant near houses. They come into leaf early and cast their leaves early, so that they exclude the spring sun and do not afford much shade in the hot autumn months, when it is often required. Trees are of value in indicating choice of residence. Rich foliage, ferns and moses tell of damp ness and alluvial deposits. Flowers and fruit trees point to dry and sunny site. Children will be healthiest where most flowers grow, and old people will live longest where our common fruits ripen best. Pines and their companions, the birches, indicate a sandy or gravel soil, elms a rich and somewhat damp soil, oaks and ashes heavy clay, pop lars and willows low, damp or marshy soil. Let then our aesthetics be tenn pered by our desires for health, and choice and abundance of trees be adapted to our sanitary needs. "-MedicGl Classics. The Sensible Arc S9ciablc.