answersLogoWhite

0

Now, it is perfectly true that four elements go a great way towards building up the world; but, setting aside the question of brewing punch, they are called carbon, hydrogen, oxygen, and nitrogen. So universal is their presence in the living and growing parts of animals and plants, that they are always spoken of as "organic elements," and science has ascertained exactly the proportion in which each should exist in a healthy condition of the human body. That body is incessantly, but imperceptibly, undergoing a process which cannot be better described than by the expression of perennial moulting, only that, whereas certain animals cast off certain parts of their body - their skin, their hair, or their feathers - every year, we lose a portion of our weight every day ; that is to say, we should lose it if we did not absorb through our lungs, the pores of our skin, and our stomachs, sufficient oxygen, carbon, hydrogen, and nitrogen, to supply the loss caused by the wear and tear of our daily life. There has even been an attempt made to prove that our vital organs are entirely renewed every forty days or so, but for this calculation there can be no really satisfactory data, although there certainly is constant loss and gain going on within us. The material for repairing this incessant waste which is the inevitable result of the activity of our nervous and muscular system, is not supplied alone by the starch, sugar, water, and fat, nor yet by the milk, meat and vegetables we consume, but by a due combination of food material which shall ensure the proper proportions of albumen, fibrine, and caseine absolutely-required by our changing frames. These are rather hard words, but their meaning will be quite plain if we take as familiar examples of the three indispensable ingredients, the white of an egg, a piece of lean meat, and a bit of cheese Everyone can understand that, although these things contain the largest proportion of one particular substance, still there may be many other substances in which they are present, all together, and it is just to teach us this, and to explain to us why we should rather give our attention to procuring one form of food than another, that a knowledge of the elements of Practical Chemistry is useful. In reading the accounts of the hardships and sufferings of explorers and travellers, we are often surprised to learn that first one member and then another of the expedition dropped down and died long before the supplies were actually exhausted. This is particularly noticeable in the account of Burke and Wills' attempt to explore the great plains of South Australia, where one by one the travellers died, not so much from sheer lack of some sort of food to eat, as from the unhappy circumstance of the only attainable food being utterly deficient in the ingredients without which the human body cannot be nourished. For instance, there was abundance of an alkaline plant on which the natives almost live at certain times of the year, and occasionally even a few fish were caught.

But these materials taken by themselves were so weak in life-supporting properties, that they failed to repair sufficiently the waste caused by severe exercise and exposure to the weather. A man may be starved to death, and yet scarcely feel hungry; that is to say, he may be able to put food into his mouth which will allay the cravings of his appetite, but which may not have the least power to nourish his body, so that he will die as surely as though he had nothing to eat.

It will perhaps only be necessary to take bread and beef as samples of food which contain in themselves every element required to build up the human frame, to repair the daily waste, and to preserve all the conditions of perfect health. The generality of mankind have found out the value of these substances for themselves without the aid of science ; but it may be as well to learn something about bread and beef, for the simple reason that as we cannot always, under all circumstances, make sure of having them as food, we may be able to select those substances which come nearest to them in nutritive value, if we understand the component parts which make them so important.

User Avatar

Wiki User

15y ago

What else can I help you with?

Continue Learning about Chemistry

What are the different chemical suffixes used to denote specific types of compounds?

Chemical suffixes are used to indicate the type of compounds. Some common suffixes include "-ane" for alkanes, "-ene" for alkenes, "-ol" for alcohols, and "-ic" for acids.


Are compounds unreactive?

Not all compounds are unreactive. Some compounds are stable and do not readily react with other substances, while others can be highly reactive and form chemical bonds with other compounds. The reactivity of a compound depends on its chemical structure and the conditions under which it is placed.


What are the properties and uses of the various suffixes in chemistry?

In chemistry, suffixes are added to the end of chemical names to indicate the type of compound or functional group present. Some common suffixes and their uses include "-ide" for binary compounds, "-ate" for salts of oxyanions, and "-ol" for alcohols. These suffixes help identify the composition and structure of chemical compounds.


What are the different chemistry suffixes used to denote specific types of chemical compounds?

Chemistry suffixes are used to indicate the type of chemical compound. Some common suffixes include "-ane" for alkanes, "-ene" for alkenes, "-ol" for alcohols, and "-ic" for acids.


What are the different kinds of compound?

A compound in chemistry is a chemical substance consisting of two or more elements. Compounds can be separated into their parent elements by chemical reaction. Some common compounds are water (H2O), carbon dioxide (CO2), and table salt (NaCl.).

Related Questions

What are some common compounds that include meitnerium?

Today any chemical compound of meitnerium was prepared.


What are the different chemical suffixes used to denote specific types of compounds?

Chemical suffixes are used to indicate the type of compounds. Some common suffixes include "-ane" for alkanes, "-ene" for alkenes, "-ol" for alcohols, and "-ic" for acids.


What are Compounds you encounter with every day?

purified water and some foods,and some objects


What are common compounds that contain plutonium?

Some plutonium chemical compounds; plutonium dioxide, plutonium nitride, plutonium carbide, plutonium nitrate, plutonium trifluoride, plutonium chloride, etc.


Do chemical compounds remain in the organism permanently?

Some do and some do not. Water-soluble compounds can pass out of an organism fairl easily. Some compounds, such as DDT, however, do not leave the body.


What are some compounds of salt?

A salt is itself a chemical compound.


What are some common compounds for carbon?

graphite


Are some chemical compounds okay for athletes to use?

Yes. For example water and the electrolytes in sports drinks are chemical compounds that athletes are actually encouraged to use.


What compounds are in strontium?

Strontium is a chemical element, so it is typically found in compounds rather than existing as a standalone substance. Some common compounds of strontium include strontium carbonate (SrCO3), strontium oxide (SrO), and strontium nitrate (Sr(NO3)2).


What are some common foods?

most common food in rarotonga


Name some chemical compounds?

Sodium chloride, Calcium oxide


What is the term for the numbers that appear in the chemical formula of some compounds?

subscripts