A Treatise on Physiology and Hygiene Part 8

[Sidenote: 25. Leavened bread? Unleavened? Hot bread?]

25. The form of bread most easily digested is that which has been "leavened," or rendered porous by the use of yeast, or by some similar method. Unleavened bread requires much more mastication. Hot bread is unwholesome, because it is not firm enough to be thoroughly masticated, but is converted into a pasty, heavy ma.s.s that is not easily digested.

[Sidenote: 26. Wheaten bread? Bread and b.u.t.ter? Experiment on the dog?]

26. Wheaten bread contains nearly every principle requisite for sustaining life, except fat. This is commonly added in other articles of diet, especially in b.u.t.ter,--"bread and b.u.t.ter," consequently, forming an almost perfect article of {73} food. The following experiment is recorded: "A dog eating _ad libitum_ of white bread, made of pure wheat, and freely supplied with water, did not live beyond fifty days. He died at the end of that time with all the signs of gradual exhaustion." Death took place, not because there was anything hurtful in the bread, but because of the absence of one or more of the food-principles.

[Sidenote: 27. State what is said of the Irish potato?]

27. THE POTATO.--The common or Irish potato is the vegetable most extensively used in this country and Great Britain. Among the poorer cla.s.ses in Ireland it is the main article of food. While it is not so rich in nutritious substances as many others, it has some very useful qualities.

It keeps well from season to season, and men do not weary of its continuous use. It is more than two-thirds water, the balance being chiefly starch, with a little alb.u.men.

[Sidenote: 28. Sweet potato? Nightshades? Potatoes when germinating?]

28. The sweet potato differs from the white or common, in containing more water and a small proportion of sugar. The common potato and the tomato belong to the same botanical order as the "nightshades," but do not possess their poisonous qualities, unless we except potatoes that are in the process of germination or sprouting, when they are found injurious as food.

[Sidenote: 29. Fruits? Use of ripe fruit? Nutriment they contain? Starch in unripe fruits? Cooking of unripe fruits?]

29. FRUITS.--These are produced, in this country, in great abundance, and are remarkable alike for their variety and delicious flavor; consequently they are consumed in large quant.i.ties, especially during the warmer months.

The moderate use of ripe fruits, in their season, is beneficial, because they offer a pleasant subst.i.tute for the more concentrated diet that is used in cold weather. The amount of solid nutriment they contain is, however, small. The percentage of water in cherries is seventy-five, in grapes eighty-one, in apples eighty-two. Unripe fruits contain starch, which, during the process of ripening, {74} is converted into sugar. Such fruits are indigestible and should be avoided: cooking, however, in part removes the objections to them.

[Sidenote: 30. How should drinking-water be as regards color and smell?

Chemically pure water? How obtained? Agreeableness of perfectly pure water?]

30. PURE WATER.--It is important that the water we drink and use in the preparation of food should be pure. It should be clear and colorless, with little or no taste or smell, and free from any great amount of foreign ingredients. Chemically pure water does not occur in nature: it is only obtained by the condensation of steam, carefully conducted, and is not as agreeable for drinking purposes as the water furnished by springs and streams. Rain-water is the purest occurring in nature; but even this contains certain impurities, especially the portion which falls in the early part of a shower; for in its descent from the clouds, the particles floating in the air are caught by the falling drops.

[Sidenote: 31. Spring and well water? Whence the sparkle, or life? The water supply of cities? Croton water? Ridgewood?]

31. Water from springs and wells always contains more or less foreign matter of mineral origin. This imparts to the drink its pleasant taste--the sparkle, or "life," coming from the gases absorbed by the water during its pa.s.sage under ground. The ordinary supply of cities is from some pure stream or pond conveyed from a distance through pipes, the limpid fluid containing generally only a small amount of impurity. Croton water, the supply of New York City, is very pure, and contains only four and a half grains to a gallon: the Ridgewood water of Brooklyn holds even less foreign matter.

[Sidenote: 32. Impurities in drinking-water? Mineral springs?]

32. Drinking-water may contain as large a proportion as sixty to seventy grains per gallon of impurity, but a much larger quant.i.ty renders it unwholesome. The mineral spring waters, used popularly as medicines, are highly charged with mineral substances. Some of them, such as {75} the waters at Saratoga, contain three hundred grains and more to the gallon.

[Sidenote: 33. What is stated of the action of water upon lead?]

33. ACTION OF WATER UPON LEAD.--The danger of using water that has been in contact with certain metals is well known. Lead is one of the most readily soluble, and probably the most poisonous of these substances in common use.

When pure water and an untarnished surface of lead come in contact, the water gradually corrodes the metal, and soon holds an appreciable quant.i.ty of it in solution. When this takes place the water becomes highly injurious: the purer the water, and the more recent the use of the metal, the greater will be the danger.

[Sidenote: 34. Lead in pipes and other things? Advice? What takes place after the articles of lead have been used much? What is wise?]

34. In cities, lead pipes are commonly used to convey water through the houses; lead being also used in the construction of roofs, cisterns, and vessels for keeping water and other liquids. After the articles of lead have been in use several months, the danger of lead-poisoning diminishes.

An insoluble coating of the sulphate of lead forms upon the exposed surface, thus protecting it from further corrosion. It is, however, a wise precaution, at all times to reject the water or other fluid that has been in contact with leaden vessels over night, or for a number of hours. Allow the water in pipes to run freely before using.

[Sidenote: 35. Coffee as an article of diet? Of what does it consist? How does the water affect the coffee? The peculiar stimulant? How does it affect most persons?]

35. COFFEE.--This is an important addition to diet, and if moderately used is beneficial to persons of adult age. As commonly employed, it consists of an infusion in boiling water of the roasted and ground berry. The water extracts certain flavoring and coloring matters, but that which gives it its peculiar stimulant qualities is the alkaloid _caffein_. With most persons its action is that of a gentle stimulant, without any injurious reaction. It produces a restful feeling after exhausting efforts of mind or {76} body; it tranquilizes, but does not disqualify for labor; and hence it is highly esteemed by persons of literary pursuits.

[Sidenote: 36. Another property of coffee? Miners of Belgium? The Caravans?

Among armies? Taken with meals?]

36. Another property of coffee is, that it diminishes the waste of the tissues, and consequently permits the performance of excessive labor upon an economical and inadequate diet. This has been tested among the miners of Belgium. Their allowance of solid food was below that found necessary in prisons and elsewhere; but, with the addition of about four pints of coffee daily, they were enabled to undergo severe labor without reducing their muscular strength. The caravans which traverse the deserts are supported by coffee during long journeys and lengthened privation of food. Among armies it is indispensable in supplementing their imperfect rations, and in relieving the sense of fatigue after great exposure and long marches. When taken with meals, coffee is also thought to promote digestion.

[Sidenote: 37. Effects of tea-drinking? Peculiar principle? The tea beverage, how made? Black and green tea? Excessive use of tea or coffee?]

37. TEA.--The effects of tea-drinking are very similar to those of coffee, and are due to a peculiar principle called _thein_. This principle is probably the same as that found in coffee, _caffein_, since the chemical composition of both is precisely alike. Tea, as a beverage, is made from the dried leaves of the plant by the addition of hot water; if the tea is boiled, the oil which gives it its agreeable flavor is driven off with the steam. There are two kinds of tea--the black and the green: the latter is sometimes injurious, producing wakefulness and other nervous symptoms. The excessive use of either coffee or tea will cause wakefulness.

[Sidenote: 38. Experiments made during Kane's expedition?]

38. During Dr. Kane's expedition in the Arctic regions, the effects of these articles were compared. "After {77} repeated trials, the men took most kindly to coffee in the morning and tea in the evening. The coffee seemed to continue its influence throughout the day, and they seemed to grow hungry less rapidly than after drinking tea, while tea soothed them after a day's hard labor, and the better enabled them to sleep. They both operated upon fatigued men like a charm, and their superiority over alcoholic stimulants was very decided."

[Sidenote: 39. State what is said of chocolate.]

39. Chocolate is made from the seeds of the cocoa-tree, a native of tropical America. Its effects resemble somewhat those of tea and coffee, but it is very rich in nutriment. Linnaeus, the botanist, was so fond of this beverage, that he gave to the cocoa-tree the name, _Theobroma_--"the Food of the G.o.ds." Its active principle is _theobromin_.

[Sidenote: 40. Use of alcoholic drinks, how general? The rule given?]

40. ALCOHOL.--The list of beverages that are consumed for the sake of the alcohol they contain is a very long one. Their use is almost universally prevalent, every civilized nation, and nearly every barbarous one, having its favorite alcoholic drink; and, as a general rule, the nations which stand the highest in civilization have the greatest varieties of these beverages,--at the same time using them the most intelligently and wisely.

[Sidenote: 41. The beverages produced by fermentation? The ardent spirits?

Grains and fruits employed? Long use of wine? Of distilled liquors?]

41. The wines and malt liquors that contain a small amount of alcohol are produced by fermentation. The beverages that hold a large proportion of alcohol, the "ardent spirits," are made by distillation. Enormous quant.i.ties of grains and fruits are thus yearly diverted from their proper uses as food; some of these being corn, wheat, rye, barley, potatoes, and rice; also the grape, apple, pear, peach, sugar-cane, cherry, fig, and orange. Wine, the fermented juice of the grape, has been in use from time immemorial, while the introduction of distilled liquors dates from a comparatively recent period. {78}

[Sidenote: 42. Describe the action of alcohol upon the human system?

Experience of Dr. Hayes and others?]

42. What is the physiological action of alcohol? Its first and most evident action is stimulation: this effect is transient, and is followed by a variable degree of depression. At first it sharpens the appet.i.te and quickens digestion, but its habitual use impairs both. This stimulation is efficient in giving the system an artificial strength during some temporary derangement, and in enabling the endurance of unusual fatigue or exposure.

The experience of Dr. Hayes, and other explorers of the polar regions, is that alcohol does not enable the body to resist the influence of cold, but, on the contrary, is always injurious.

[Sidenote: 43. Another property of alcohol? How do we explain the restorative influence of wines and liquors?]

43. Another property it has in common with tea and coffee. It supports the powers of life, economizes food, and r.e.t.a.r.ds the waste of tissues; in other words, it "banks the fires," and prevents their burning wastefully. On this principle we explain the restorative influence of wines or liquors during exhausting diseases, in convalescence, and after excessive labors of mind or body.

[Sidenote: 44. Alcohol, a poison? Moderate stimulants? Prevailing opinion?

Hence?]

44. Pure alcohol, or an excessive quant.i.ty of ardent spirits, is an undoubted poison, and has been frequently known to produce fatal results.

Stimulants in moderate quant.i.ties have been thought to increase strength, and in this view they have been called "alcoholic foods." This is not now conceded by scientific men. The prevailing opinion is, that they serve no useful purpose as an article of diet, and that their beneficial influence is limited to cases where the system is enfeebled, where some unnatural demand is made upon the vital powers, or where the supply of food is insufficient. Hence, while alcohol has not the power to build up, it may obstruct the process of pulling down. {79}

QUESTIONS FOR TOPICAL REVIEW.

PAGE 1. How is the necessity for food shown? 64 2. To what process of waste and repair is the body constantly subjected? 64 3. How do you account for the sensations of hunger and thirst? 65 4. What further can you state having relation to the subject? 65 5. What can you state in regard to the quant.i.ty of food required for the support of life? 65, 66 6. What circ.u.mstances change the needs of persons, old and young, as regards food and drink? 65, 67 7. What becomes of all the food and drink we consume? 66 8. What further can you state in relation to the process of renovation through which the body pa.s.ses? 66 9. What can you state of the habits of nations in respect to diet? 66, 67, 69 10. What in relation to the selection of articles for food? 67 11. What as respects the necessity for changing or varying the diet? 67 12. What has been proved as regards animal food? 67 13. Of what importance is milk as an article of food? 67, 68 14. What are the const.i.tuents of milk? 68 15. What can you state of eggs as an article of food? 68 16. Of the meats, so called, as an article of food? 68, 69 17. What effect does cold have upon meats? 69 18. In what other way may beef and pork be preserved? 69 19. What can you state of salted meat as food, and of its continued use? 69 20. What change does meat undergo in the cooking? 70, 71 21. What directions are given for boiling meat? 70 22. What for roasting, and with what results? 70, 71 23. What is said about the frying of meats? 71 24. Give the statement in relation to trichina. 71 25. State what is said in relation to fish. 71 26. What is stated of the usefulness and other properties of the products of the vegetable kingdom? 71, 72 27. What further is said of vegetable food? 71, 72 28. Why is bread made of wheat flour so important as an article of food? 72 29. State whatever else you can in relation to bread. 72, 73 30. Give the statement respecting the potato. 73 31. What is stated of fruits, the use of them, their nutritious qualities, etc.? 73, 74 32. How general is the existence of perfectly pure water? 74 33. What is stated in relation to drinking water? 74, 75 34. How does the action of water upon lead affect lead? 75 35. What further can you state on the subject? 75 36. What properties has coffee as an article of diet? 75, 76 37. In what circ.u.mstances has coffee been found peculiarly beneficial? 76 38. What comparison is made between coffee, tea, and chocolate? 76 39. How are the wines, and malt and other alcoholic beverages produced? 77 40. What articles are employed in their production? 77 41. Describe the physiological action of alcohol. 78 42. What comparison is made between tea, coffee, and alcohol? 78 43. What can you state of alcohol, as a poison, a stimulant, and article of diet? 78 44. What, then, can be said of alcohol as a recommendation? 78

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