The influence exerted upon the process of osmosis in the body is one of the most important parts played by the mineral salts in metabolism.
The phenomena of osmosis are naturally of the first importance in the action of organisms, and for a long time have attracted the attention of naturalists.
The laws of cryoscopy, of tonometry, and of osmosis thus again become strict, and no exception to them remains.
We must notice, however, that the physical force of osmosis is not the only factor concerned in absorption.
This process of osmosis lies at the basis of the absorption of food from the alimentary canal.
The force of osmosis has no special connection with life.
Now when this blood in its circulation flows through the active tissues--for instance, the muscles--it is again placed under conditions where osmosis is sure to occur.
Although these droplets are of microscopic size they are not actually in solution, and therefore not subject to the force of osmosis which only affects solutions.
Osmosis takes place when two fluids of different osmotic pressure are separated by animal membrane.
These harmful substances may be rendered soluble by combination with sugars and so transposed by osmosis to some other part of the plant.
Air is brought to this thin respiratory membrane and by osmosis the oxygen passes through the membrane and through the thin walls of the fine blood-vessels, and is taken up by the blood.
By osmosis the oxygen of this air passes in through the gill-membranes, while the carbonic acid gas brought by the blood passes out through them.
Osmosis is "the passage of a fluid through a membrane"; it is a chemical process, caused by the chemical affinity between two liquids or gases separated one from the other by a porous diaphragm or substance.
But a deeper insight into the physiology of these organs was only possible when the meaning of the phenomena of osmosis had been rendered clearer by the researches of Pfeffer and De Vries in 1877.
The inner wall of the intestine is not a lifeless membrane, andosmosis will not solve the mystery.
The study of the organizing action of osmosis on organic material has as yet been hardly attempted.
Of all the ordinary physical forces, osmotic pressure and osmosis alone appear to possess this remarkable power of organization and morphogenesis.
It has long been known that diffusion and osmosis may determine various chemical transformations.
Diffusion and osmosis are the elementary phenomena of life.
It is going on continually in the tissues of all living beings, and a study of the laws of diffusion and osmosis is therefore absolutely necessary for a just conception of vital phenomena.
An osmotic growth has an evolutionary existence; it is nourished by osmosis and intussusception; it exercises a selective choice on the substances offered to it; it changes the chemical constitution of its nutriment before assimilating it.
It is a matter of astonishment that the scientist has taken no notice of the active part which osmosis has played in the evolution of our earth.
If salt is put into the water in which potatoes and other vegetables are boiled, osmosis is set up and a current of water passes from the vegetable cells to the salt water.
Of all the theories as to the origin of life, that which attributes it to osmosis and looks on the earliest living beings as products of osmotic growths is the most probable and the most satisfying to the reason.
Hence the study of the physics of diffusion and osmosis is the very basis of synthetic biology.
Osmosis produces growths of great complexity, much more complicated indeed than the more simple forms of living organisms.
The first experiment in physiogeny was the discovery of osmosisby the Abbe Nollet in 1748.
If you will turn back for a moment to the beginning of the description of how plants get their food, you will find that in osmosis the weaker liquid tends to permeate the denser one more rapidly than the denser one does the weaker.
As we have seen, osmosisis a purely mechanical process which, if left to operate without interference, would not aid but injure the plant.
While we have just said it is a gentle pressure, that is true only in the case where the osmosis has free play, and the pressure is stopped with the perfect mixing of the two liquids.
When the flow of liquids in osmosis is not at once equalized, a gentle pressure is brought to bear to make them so.
It is characteristic of a dicresylmethanedisulphonic acid purified by electro-osmosis that it does not precipitate aniline hydrochloride.
A Neradol D purified by electro-osmosis finally yielded a pure solution of dicresylmethanedisulphonic acid, which precipitated gelatine and exhibited pronounced tanning effects, but gave a greenish-black coloration with iron salts.
Especially the first stage of the electro-osmosis produces a cathodic migration of the phenols, which may then be detected at a cathode by means of the iron and bromine reactions.
The interchange of gases at the lungs, however, is not fully understood, and it is possible that other forces than osmosis play a part.
In the body osmosis takes place between the blood and the lymph and between the lymph and the cells, the movements being through the capillary walls and the membranes inclosing the cells (Fig.
With a special piece of apparatus, known as an osmosometer, the principle of osmosis may be more easily illustrated than by the method in either of the above experiments (Fig.
Osmosis may be shown by suitable experiments (see Practical Work) to take place under the following conditions: 1.
The cause of osmosis is the motion of the molecules, or minute particles, that make up the liquid substance.
Its respiratory function consists in allowing oxygen and carbonic acid gas to pass by osmosis between the embryonic and the maternal blood.
The cell absorbs oxygen from the water by osmosis through its delicate membrane, giving up carbon dioxide in return.
Illustration: Experiment showing non-osmosis of starch in tube A, and osmosis of sugar in tube B.
Food passes by osmosis through the membrane and by osmosis through the thin walls of the blood vessels.
The carbon dioxide is taken in through the stomata and reaches the green cells by way of the intercellular spaces and by osmosis from cell to cell.
Without the process of osmosis we should be unable to use much of the food we eat.
Non-osmosis of non-digested foods, comparison between osmosable qualities of starch and grape sugar.
It is not an exaggeration to say that osmosis is a process not only of great importance to a plant, but to an animal as well.
These digestive enzymes change the starch of the bread to sugar and the protein to a soluble form which will pass by osmosis into cells of the mold.
Food substances in solution may be soaked up as a sponge would take up water, or they may pass by osmosis into the cells lining the villus.
No breathing organs are seen, because osmosis of oxygen and carbon dioxide may take place anywhere through the cell membrane.
We have already seen that in an exchange of fluids byosmosis the greater flow is always toward the denser fluid.
The pressure created by this process of osmosis is sufficient to send water up the stem to a distance, in some plants, of 25 to 30 feet.
It is by osmosis chiefly that the raw, nourishing material in the blood gets into the flesh lying about the capillaries.
By osmosis the blood nourishes and purifies the flesh.
By osmosis the blood is itself nourished and kept pure.
It is by osmosischiefly that food gets out of the stomach into the blood.
