That which is worn for a long time becomes saturated with the excretions and exhalations of the body, which prevent free transpiration from the pores of the skin, and thereby induce mental inactivity and depression of the physical powers.
The greatest factor, however, is transpirationof water from leaves.
It is commonly said that there is a great difference between the transpiration and evaporation of water in plants.
Leclerc has very carefully examined this question, and he concludes thattranspiration is only the simple evaporation of water.
In a word, transpiration and evaporation is the same thing.
As to transpiration taking place in a saturated atmosphere, it is a mistake; generally there is a difference in the temperature of the plant and the air, and the air is not saturated in its vicinity.
How can the laws of time and space, as involved in the transpiration of human character,--how can these be applied in a place where the mind is thus absolved from their proper jurisdiction?
In short, their whole transpirationproceeds by the laws and from the blood of mutual membership.
Hales of course knew nothing of stomata, but it is surprising to find Sachs in 1865 discussing the problem of transpiration with hardly a reference to the effect of stomatal closure.
We now for the moment leave the subject of transpiration and pass on to that of root-pressure on which Hales is equally illuminating.
The transpiration of the leaves may be so increased that the roots cannot repair the loss.
And on the other hand, a too low temperature of the soil may so diminish the action of the roots that even a small loss by transpiration cannot be repaired.
Occasionally, on the other hand, it is said to come from sitting on heavily cushioned chairs, particularly leather chairs which do not allow of much transpiration and cause a feeling of uncomfortable heat.
The basal leaves and lower part of the stiff stem, especially, are hairy, not to allow too free transpiration of precious moisture.
Plants choosing such habitats as they have adopted, usually in tropical or semi-tropical regions, had to resort to various expedients to save loss of water through transpiration and evaporation.
These leaves are smooth and green above, silvery on the under side, with fine white hairs, adapted for protection from excessive sunlight and too rapidtranspiration of precious moisture.
Moisture is rapidly absorbed from the air by the leaves, and from the earth by the roots, and is again all returned to the air and earth by transpiration or exudation.
Trees also have a cutaneous transpiration by their leaves.
More important results were obtained from the study of a class of phenomena corresponding to the transpiration of gases through India-rubber or metallic septa.
Chilling the surface and checking cutaneous transpiration appear to be the immediate cause of this inflammation in a considerable proportion of cases.
The skin is hot and dry, and cutaneous transpiration nearly checked.
LOSS OF SOIL WATER By surface wash By percolation and leaching By evaporation By transpiration How to check these losses 53 VII.
As a resulttranspiration from the leaf may be excessive.
This upward movement of water is very much increased, in the case of soil covered with vegetation, by the transpiration of the plants.
This latter condition is accounted for by the enormous transpiration of water which takes place through the trees, especially in summer-time, which is such as to render the soil almost air-dry.
Transpiration is loss of water by the plant by evaporation, chiefly from the minute pores or stomata on the leaves.
Although transpiration is a necessary accompaniment of nutrition, it may easily become excessive, especially where the plant cannot readily recoup itself.
The comparative dryness of the atmosphere in spring also causes a greater amount of transpiration then than in autumn and winter.
Fourth, transpiration increases with the increase of direct sunlight.
Yet transpiration appears to be a process wholly necessary for plant life.
The fertilizing of lands with proper plant-foods, as shown in the last sections, tends to check transpirationand makes possible the production of dry matter at the lowest water-cost.
It does not follow, however, that the more vigorously a crop grows, the more rapidly does it transpire water, for it is well known that the most luxuriant plant growth occurs in the tropics, where the transpiration is exceedingly low.
Fourthly, transpiration apparently influences plant growth and development in a number of ways not yet clearly understood.
This last mentioned value oftranspiration is especially important in dry-farm districts, where, during the summer, the heat is often intense.
Second, transpirationincreases with the increase in temperature; that is, under conditions otherwise the same, transpiration is more rapid on a warm day than on a cold one.
Some of the conditions influencing the transpiration may be enumerated as follows:-- First, transpiration is influenced by the relative humidity.
Third, transpiration increases with the increase of air currents, which is to say, that on a windy day transpiration is much more rapid than on a quiet day.
The fact that transpiration is greater under a low relative humidity is of greatest importance to the dry-farmer who has to contend with the dry atmosphere.
Seventh, transpirationvaries also with the age of the plant.
Plant-food and transpiration It has been observed repeatedly by students of transpiration that the amount of water which actually evaporates from the leaves is varied materially by the substances held in solution by the soil-water.
They produce a cutaneous transpiration by the leaves.
The consequent arrest of the transpiration current and the proper supply of nutriment to the cambium and cortex explain the phenomena.
For instance, the stomata open and close to different extents according to the conditions of light and moisture, and this affects the whole mechanism of transpiration especially, and therefore the supplies of water and mineral salts.
Yellowing accompanied by Wilting is a predominant symptom in most cases where transpiration is more active than root-absorption beyond a certain limit, as is well known in cases of prolonged drought.
In many of these cases the dying-back of the twigs is expedited owing to the mycelium invading the medullary rays and wood vessels, and so obstructing the transpiration current.
Transpiration induces relatively enormous disturbances of equilibrium, and does work in moving water quite independent of chemical energy.
In other cases Fungi, and even Bacteria, have been found to have made their way into the principal vessels, the lumina of which they stop up, thus reducing the transpiration current.
Syringing to check transpiration from the foliage is very useful with plants which are recently transplanted.
As the wind is more and more felt, and increases the dangeroustranspiration of winter the trees become more and more dwarfed to escape its force.
Transpiration takes place faster in a tall plant like a tree, which grows up into dry layers of the air, than in a low plant like a grass.
Both the grasses and their associated herbs are well protected against too violent transpiration which their exposure to nearly continuous sunshine, high summer heat, and very considerable winds makes particularly active.
This happens to a considerable number of plants, during the night when transpiration is laggard, and such drops are usually mistaken for dew.
Every device both to retard transpiration and to store up water to last over a completely rainless period, may be found.
In most kinds these branches are green, assume the functions of leaves, such as transpiration and the manufacture of food by photosynthesis.
In this plant the leaf base, as though to be ready for whatever change transpiration or photosynthesis may demand, is so attached to the stem that such changes are made with the least possible delay or wrenching.
On the one hand there is the absolute necessity for light, on the other the ever-present danger that the response of leaves to this necessity will result in a transpiration rate too rapid to be held in check by the guard cells.
While some of these movements have already been hinted at as a possible response to transpiration or too intense light, there are others where the advantage to the plant, if any, has yet to be demonstrated.
The hairy covering of leaves is well worth observation, as it may hide not a few facts about transpiration and, in some leaves, has had much to do with their preservation from grazing animals.
Perhaps the best illustration of how high transpiration both in plants and in man may be in such regions is gained by a statement of D.
The colored leaves in the predominantly dark green and gloomy rain forest, because of their greater absorption of light and consequently higher transpiration rate, are of decided advantage.
Among the plants which have been successfully employed in the drainage of marshy soil bytranspiration probably the species of Eucalyptus (notably E.
The amount of water taken from the soil by the trees of a forest and passed into the air by transpiration is not so large as that accumulated in the soil by the diminished evaporation under the branches.
But if the trees are so scattered as not materially to reduce evaporation from the ground, the effect of transpiration in diminishing the moisture of the soil is readily shown.
Through the stomata, when open, free interchange may take place between the external air and that within the leaf, and thus transpiration be much facilitated.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "transpiration" in a variety of sentences. We hope that you will now be able to make sentences using this word.
