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Iron reworked in body
612
CURRENT TOPICS.
[J. F. I.
No Substitutes Oust Wood As Tie -Material.--More than 2,500 patents have been granted in the last 50 years for railroad tie materials other than wood, says the booklet, Products of American Forests, issued by the United States Department of Agriculture. But in general, railway traffic continues to move on a wood foundation. J. Alfred Hall and T. J. Mosley,. of the Forest Products Laboratory, estimate that about a billion wooden ties are in service. There is an annual renewal of about IOO ties to the mile, on the average, but several important railroads get along with yearly renewals of 50 to 75 ties a mile. This longer life of the tie results from better roadbed, better construction methods, and chemical In recent years railroads have been treatments with preservatives. buying about 50,000,000 ties a year, compared with nearly 150,000,ooo thirty years ago. Three-quarters of the ties are now treated before they are laid. Cheapness, strength, elasticity, resistance to shock, ease of replacement, and electric insulating properties are qualities of wood ties that account for the demand that promises a continuing market for this staple product of American woodlands. R. H. 0. Iron Reworked in Body.-The human body, like industry, uses iron over and over again, says an article by Miss MABEL A. DICKSON Although the body conin the current Yearbook of Agriculture. tains only a little more iron than there is in a shingle nail, it is essential in the red coloring matter of the blood to make the blood an effective carrier of the oxygen the body requires in its chemical service to the living cells. These blood cells break down, but not much of the iron is wasted. About 85 per cent., Miss Dickson explains, is salvaged and goes finally to what corresponds to a factory-the bone marrowfor the formation of new red cells. So effective is this process of iron conversion and reuse that an average adult male needs to absorb daily from his food only about one-sixth as much iron as the body requires in one day to make red blood cells. The body is able to store a moderate reserve of iron, but a fairly regular and adequate intake of iron is essential to continued good health. Another article in the yearbook lists more than 30 excellent sources of iron and a score of good sources. These include most of the green-colored vegetables, lean meats, poultry, eggs, oysters and shrimps, several dried fruits, whole ground cereals, molasses, legume seeds, and liver, heart, and kidneys. R. H. 0.
CURRENT TOPICS.
[J. F. I.
No Substitutes Oust Wood As Tie -Material.--More than 2,500 patents have been granted in the last 50 years for railroad tie materials other than wood, says the booklet, Products of American Forests, issued by the United States Department of Agriculture. But in general, railway traffic continues to move on a wood foundation. J. Alfred Hall and T. J. Mosley,. of the Forest Products Laboratory, estimate that about a billion wooden ties are in service. There is an annual renewal of about IOO ties to the mile, on the average, but several important railroads get along with yearly renewals of 50 to 75 ties a mile. This longer life of the tie results from better roadbed, better construction methods, and chemical In recent years railroads have been treatments with preservatives. buying about 50,000,000 ties a year, compared with nearly 150,000,ooo thirty years ago. Three-quarters of the ties are now treated before they are laid. Cheapness, strength, elasticity, resistance to shock, ease of replacement, and electric insulating properties are qualities of wood ties that account for the demand that promises a continuing market for this staple product of American woodlands. R. H. 0. Iron Reworked in Body.-The human body, like industry, uses iron over and over again, says an article by Miss MABEL A. DICKSON Although the body conin the current Yearbook of Agriculture. tains only a little more iron than there is in a shingle nail, it is essential in the red coloring matter of the blood to make the blood an effective carrier of the oxygen the body requires in its chemical service to the living cells. These blood cells break down, but not much of the iron is wasted. About 85 per cent., Miss Dickson explains, is salvaged and goes finally to what corresponds to a factory-the bone marrowfor the formation of new red cells. So effective is this process of iron conversion and reuse that an average adult male needs to absorb daily from his food only about one-sixth as much iron as the body requires in one day to make red blood cells. The body is able to store a moderate reserve of iron, but a fairly regular and adequate intake of iron is essential to continued good health. Another article in the yearbook lists more than 30 excellent sources of iron and a score of good sources. These include most of the green-colored vegetables, lean meats, poultry, eggs, oysters and shrimps, several dried fruits, whole ground cereals, molasses, legume seeds, and liver, heart, and kidneys. R. H. 0.