H E N R Y ' S 
 OUTLINES OF SCIENCE. 
 
 JOSEPH FERNANDEZ. B.A.. LL.D., 
 
 AUTHOR OF " HKNET'S SCHOOL GEOGRAPHY," " HEKBY'S DICTA- 
 
 IIO>'," " HEKEl's SClilPTUEB HISTOBT," ETC., ETC. 
 
 THIRD EDITION, 
 
 LONDON: 
 
 CHARLES BEAN, 81, NEW NORTH ROAD, HOXTON, N 
 1872.
 
 PREFACE. 
 
 THE following series of lessons on the Elements of 
 Science has been prepared to meet a want which has 
 been strongly expressed to the Author by many of 
 the multitude of teachers who have done him the 
 honour to adopt his other educational works. 
 
 Without attempting a complete epitome of any of 
 the sciences discussed, it is hoped that sufficient infor- 
 mation is given to render the book a good introduction 
 to a fuller study of the subjects. 
 
 Pains have been taken to direct attention as far as 
 possible to what are called common things. 
 
 Numerous questions on the text have been added. 
 
 Eagle House, Tottenham, 
 January, 1871. 
 
 2091254
 
 OUTLINES OF SCIENCE. 
 
 ASTRONOMY. 
 
 CHAPTEE L 
 
 Astronomy is the science which treats of the 
 heavenly bodies ; their sizes, motions, distances, 
 periods, and the order in which they move. 
 
 The term Astronomy is derived from two Greek 
 words, a<srr t p (aster), a star, and vofios (nomos), a law. 
 
 The Solar System consists of the planetary bodies 
 with their satellites or atten- 
 dant moons, which pass round 
 Sol, the sun, and are influenced 
 by its light and heat. 
 
 In the present system, which 
 is called Pythagorean, from 
 Pythagoras, an old Greek phi- 
 losopher, who lived B.C. 550, 
 the sun is the centre of all the 
 other planets, 
 
 Ptolemaic System. For many centuries the system 
 of Pythagoras was not accepted, but men insisted 
 that the earth was a flat surface, and that the sun 
 went round it, or rather went over it, during the day, 
 and having passed under it, came up again at the 
 other side.
 
 6 OUTLINES OF SCIENCE. 
 
 Ptolemy, a celebrated astronomer of Egypt, who 
 lived at Alexandria in the second century, A.D. 130, 
 placed the earth in the centre of the universe, and 
 made all the other planets revolve round it. 
 
 Copernictts. From the time of Ptolemy, until the 
 sixteenth century, little progress was made in the 
 science, but in A.D. 1500, Copernicus, a native of 
 Thorn, in Prussia, began the study, and during the 
 next thirteen years published works on the subject, 
 in which he set aside the Ptolemaic System, and in- 
 troduced that which is now generally received as the 
 Copernican System, in which the sun is the centre, 
 and all other planets revolve round it. 
 
 His opinions met with violent opposition, and he 
 died in 1513, worn out with anxiety and excessive 
 labour in the pursuit of his favourite study. 
 
 Tycho Brahe. Tycho Brahe, who lived in the 
 same century, and who was a native of Denmark, 
 rejected the theories of Ptolemy and Copernicus, and 
 maintained that the earth was in the centre, and that 
 the sun revolved round the earth, while all the other 
 planets similarly revolved round the sun. This cum- 
 brous method was believed in until gradually argued 
 away, and replaced by the Copernican, in the various 
 works of Kepler, Galileo, Newton, Halley, Herschel, 
 and other more recent astronomers. 
 
 Primary Planets. In the Solar System all the 
 planets which revolve round the sun are called Pri- 
 mary, and the number, as discovered hitherto, amounts 
 to eight, besides the sun itself. These are as follows : 
 reckoning from the sun MERCURY, VENUS, EARTH, 
 MARS, JUPITER, SATURN, URANUS, and NEPTUNE. 
 These vary greatly in size, as well as in the diameter 
 of their orbit or travelling path, and in distance from 
 the sun. They may be known by their steady light 
 and the absence of twinkling. Several of them have
 
 ASTRONOMY. 7 
 
 secondary planets or moons, called satellites or atten- 
 dants, which pass round them in stated periods, just 
 as our moon travels round the earth. While the 
 Earth has one moon, Jupiter has four, Saturn has 
 eight, Uranus has six, and probably more, and Nep- 
 tune one, as far as is yet known. 
 
 Planetoids, or little Planets. Between the orbits 
 of Mars and Jupiter there is a greater space in pro- 
 portion, than between the other planets, and there 
 are many small bodies, all of which have been dis- 
 covered within the present century, and many during 
 the past twenty years, since the size and power of 
 the telescope have been so much increased. Before 
 1847, the only planetoids, or asteroids, as they are 
 commonly called, known to astronomers, were Ceres, 
 Pallas, Juno, and Vesta, which were discovered 
 between 1801 and 1807. 
 
 QUESTIONS ON CHAPTER I. 
 
 Of what does Astronomy treat ? 
 
 From what words is Astronomy derived? 
 
 Of what docs the Solar System consist ? 
 
 Who was Pythagoras ? When did he live ? 
 
 What was the peculiarity of the Ptolemaic System ? 
 
 What name is given to the Solar System at present ? 
 
 Who rejected the Copernicaii theory ? Who accepted it? 
 
 Xsime the primary planets in their order from the sun ? 
 
 What are the secondary planets ? What is a satellite ? 
 
 Where are the planetoids ? Name the four largest ? 
 
 When and where did the astronomer Ptolemy live? 
 
 How many moons or satellites has Jupiter ? 
 
 How may the planets be distinguished, from the stars ? 
 
 CHAPTER II. 
 
 THE EAKTH. 
 Form of the Earth The earth, being the planet
 
 8 OUTLINES OF SCIENCE. 
 
 which we inhabit, is of most interest and importance 
 to us. For many ages people thought that the world 
 was flat, and the old writers of Greece and Eome 
 speak of the ends of the world, and of the Ultima 
 Thule, the most distant or last regions. Thales, who 
 lived about B.C. 609, had a notion that the world was 
 round. 
 
 We have many proofs of its rotundity or roundness. 
 The proof so common in our books on geography is 
 most familiar, which notices that a vessel on leaving 
 the sea-shore is lost sight of by degrees, and that the 
 main-topmast disappears last, which it would not do 
 if the earth were flat, because it is easier to see the 
 large hull of a ship, than the small spars at the top 
 of it. 
 
 Again, if two ships at sea are one mile apart, the 
 water rises eight inches above the level ; if two miles 
 apart, four times eight inches ; if three miles apart, 
 nine times eight inches ; and so on, the height of the 
 water increasing in similar proportion as the square 
 of the distance increases. 
 
 Another more conclusive proof is that caused by a 
 lunar eclipse, that is, an eclipse of Luna, the moon. 
 When the earth comes exactly between the sun and 
 the moon, the shadow of the earth is cast upon the 
 lunar surface. This is always round, and it may 
 easily be proved that only a round body can in all 
 positions cast a circular shadow. 
 
 Diurnal Motion. The earth turns round upon its 
 own axis or centre from west to east, once in about every 
 twenty-four hours ; this motion causes the alternation 
 of day and night. We do not notice this motion, 
 because everything on the surface of the globe, and in 
 the atmosphere, is carried along with it. 
 
 Because of this motion, the sun appears to rise in 
 the east, and to move across the heavens in a certain
 
 ASTRONON\T. 9 
 
 path, which is called the ecliptic ; and the clusters of 
 stars, called constellations, also appear to do so. 
 
 As all the works of God show such manifest wisdom, 
 as well as adaptation, we may regard it as certain 
 that bodies of such great size and at such vast dis- 
 tances, do not go round the earth. During twenty-four 
 hours, nearly every part of the earth's surface comes 
 opposite the sun. We therefore travel at the rate of 
 one thousand miles an hour. 
 
 It is easy to understand from this diurnal motion, 
 that while the people who are opposite the sun 
 enjoy his noon-day or meridian heat, those who 
 are on the opposite side of the world are in the 
 darkness of midnight. This will account for the fact 
 that when it is twelve o'clock noon at Greenwich, it is 
 twelve midnight in Van Diemen's Land, seven o'clock 
 at Philadelphia, and so on at intermediate places. 
 
 The earth is not exactly round, because a line 
 drawn round its equator would be 26^ miles longer 
 than a similar line drawn round it from pole to pole. 
 The equatorial diameter is therefore so much longer 
 than the polar. 
 
 It is therefore called an oblate spheroid, which 
 means that it is flattened a little at the poles like an 
 orange. It is believed that the difference is caused 
 by the rapid motion, which causes it to bulge at the 
 equator, while it is a little diminished at the poles. 
 
 QUESTIONS ON CHAPTER II. 
 
 What was the opinion of Thales ? When did he live ? 
 
 Give three proof's of the rotundity of the earth. 
 
 What is meant by the diurnal motion of the earth? 
 
 What is the result of the daily motion ? 
 
 What is the ecliptic? What are constellations ? 
 
 When it is noon at Greenwich, what time is it in Australia? 
 
 What is an oblate spheroid ? What makes the earth one ? 
 
 In which direction does the earth turn ?
 
 10 OUTLINES OF SCIENCE. 
 
 Hence where does the sun appear to rise ? 
 
 .At what rate do we travel on the earth's surface? 
 
 Why is the Copernican theory most reasonable ? 
 
 CHAPTER III. 
 
 ANNUAL MOTION. 
 
 Annual Motion. Besides its motion on its own 
 axis, the earth travels round the sun in 365 days, 5 
 hours, 48 minutes, and 49 seconds, or, as we usually 
 say, in 365^ days. This motion is the cause of the 
 difference of the seasons, and also in the length of 
 days and nights in various parts of the globe. 
 
 This motion is proved by observing the passage of 
 the sun through the ecliptic, when it will be noticed 
 that his position changes a little every day until, in 
 the course of a year, he passes through all the con- 
 stellations of the Zodiac. 
 
 Thus, in January he is in Capricorn, in March in 
 Aries, while in June he is in Cancer, and in September 
 in Libra, and during this annual motion the seasons 
 are constantly changing. 
 
 To understand the cause of this, we must look at 
 the figures which follow. If, as in Fig. 2, the axis of 
 the earth were perpendicular, we 
 should have equal day and night 
 all over the earth, because the 
 same half of the earth would 
 Fig. 2. always be twelve hours within the 
 
 li-ht of the sun. In this case the parts of the earth 
 opposite the sun would be excessively hot, while the 
 polar regions would be as cold in comparison a man 
 living on the parallel of latitude E, would always 
 enjoy a temperate climate, and not be subjected to 
 change of season.
 
 ASTRONOMY. 1 1 
 
 The fast is, however, that the axis or pole of the 
 earth is not perpendicular or up- 
 right, but inclined 23^ degrees, as 
 in Fig. 3. In its path round the fy A 
 sun, the axis is always kept thus, 
 and consequently all the parts of Fig. a 
 
 the earth are warmed and lighted in turns, in propor- 
 tion as they receive the direct rays of light and heat 
 The people who live on the equator have always day 
 and night of the same length, that is twelve hours ; 
 the people at the poles, if there be any, have a day 
 six months long, and a night six months long, because 
 each pole is within the sun's rays for that period of 
 the year. The nearer the equator, the less is the 
 difference between the length of the day and night, 
 while the nearer the poles, or the higher the latitude, 
 the greater is the difference in their length. 
 
 The Seasons. These vary as the length of day and 
 night varies. From Fig. 3, it will be seen that a per- 
 son who lives at A will be on a parallel, which in the 
 summer season of the year will be in the sun's light 
 sixteen hours, and in the winter season only eight 
 hours. Consequently that parallel will receive more 
 heat in sixteen hours than it will part with in the 
 following eight, and the heat increases as the days 
 lengthen, and even for some time beyond. Thus 
 July and August are usually hotter than June. In 
 winter the opposite will be the case, and the cold of 
 the long nights will not be removed by the warmth of 
 the short days. Hence the old winter adage 
 
 "As the day lengthens, the cold strengthens." 
 
 In the months of March and September the axis of 
 the earth does not decline in either direction, and on 
 those occasions the days and nights are equal all over 
 the world. These are called the vernal and autumnal 
 equinoxes.
 
 12 
 
 OUTLINES OF SCIENCE. 
 
 Dimensions. The circumference (or measure round) 
 of the earth is found to be 24,907 miles, which is 
 therefore the length of the equator, and of all other 
 great circles. In Fig. 2, all lines drawn round the 
 earth passing through the poles are great circles, and 
 are called meridians. As these pass through the 
 equator, they are used to measure longitude, east or 
 west. 
 
 All circles which pass round the earth parallel 
 to the equator, and either north or south of it, are 
 called parallels of latitude, because by means of them 
 altitude is measured, north or south. 
 
 The diameter of the earth from pole to pole is 7899 
 miles, and through from the equator to the opposite 
 side is 7926 miles nearly. 
 
 Orbit and Distance from the Sun. The orbit or 
 
 path in which the 
 earth travels round 
 the sun, is in the 
 form of an ellipse, 
 or of a circle drawn 
 out a little. The 
 sun is in the posi- 
 F>g- * tion of one of the 
 
 nodes of the ellipse, so that the earth is nearer the 
 sun at one period of its course than at another. 
 
 This happens in winter, when the world is nearest 
 to the sun, but as it moves quicker, it does not appear 
 to derive any increase of heat. The greatest distance 
 of the earth from the sun is 93,000,000 miles, its 
 least distance 90,000,000 miles. The mean or 
 average distance is therefore 91,350,000 miles. Until 
 recently it was said to be 95,000,000 miles. 
 
 QUESTIONS ON CHAPTER III. 
 What is the annual motion of the earth ?
 
 ASTRONOMY. 13 
 
 What is tlie result of this annual motion ? 
 
 How can this annual motion be discoyered ? 
 
 What would happen if the earth's axis were upright? 
 
 What is its amount of inclination ? 
 
 What is the length of day on the equator ? 
 
 How are the seasons said to vary ? 
 
 When is the effect of accumulated heat or cold felt most ? 
 
 In -what months are the vernal and autumnal equinoxes ? 
 
 What is the circumference of the earth ? Its diameter ? 
 
 What is a meridian ? and what a parallel ? 
 
 What is the earth's orbit ? What is its form ? 
 
 When is the sun nearest to the earth ? 
 
 What is the greatest distance between them ? And the arerage ? 
 
 CHAPTEE IV. 
 
 Longitude. As the circumference of the earth is 
 over 24,000 miles, it follows that the sun's light passes 
 over it at a rate of more than 1000 miles an hour. 
 The equator, which is a great circle, is divided into 
 360 degrees, this divided by 24 gives 15, the number 
 of degrees passed over in every hour. 
 
 The longitude of a place, is the difference between 
 the clock time at Greenwich, and the clock time at 
 any other place, reckoning fifteen degrees per hour, or 
 one degree for every four minutes. 
 
 Thus the captain of a ship who finds the sun at its 
 meridian frhen his Greenwich-corrected chronometer 
 is at ten o'clock, will know that his longitude is two 
 hours east, or thirty degrees east. Should he find the 
 sun reaching its meridian when his chronometer marks 
 two o'clock, he will similarly know that his longitude 
 is two hours, or thirty degrees west. 
 
 Chronometers. It is of the utmost importance that 
 these chronometers should keep exact time, otherwise 
 finding the longitude by this process would be uncer- 
 tain, and consequently dangerous to the navigator. 
 
 2
 
 14 OUTLINES OF SCIENCE. 
 
 Chronometers were brought to great perfection by 
 John Harrison, of London, who received a reward of 
 20,000 for some which enabled captains to find out 
 their position within thirty miles, after a long voyage. 
 This was in 1787, and they have since been much 
 improved. 
 
 Latitude. To find latitude, which is the distance 
 north or south of the equator, the observer must fix 
 on some of the heavenly bodies and find their altitude 
 or height above the horizon, when they come to their 
 meridian. As the times of the meridian of the sun 
 and all the heavenly bodies, with many other par- 
 ticulars, are given in nautical almanacs, the observer, 
 having found the longitude also, is able to see his 
 exact position on the surface of the ocean. 
 
 Tides. There is an ebb and flow of all the waters 
 on the globe twice in about twenty-five hours (twenty- 
 four hours fifty minutes). This is caused by the 
 attraction of the sun and moon. It was discovered 
 by Sir Isaac Newton, that substances are kept in their 
 places while rolling through space at the rate of 1000 
 miles an hour, by a force called the attraction of 
 gravitation ; and all the heavenly bodies in the Solar 
 System are influenced by this force, so as to be kept 
 in their orbits. 
 
 As the moon passes round the earth in her orbit, 
 ..WIG r/o, tlie tides appear to 
 follow, as if at- 
 tracted by her. 
 They are always 
 highest on the side 
 next the moon, but 
 there are also tides 
 on the side opposite 
 n &. 5 - the moon, because 
 
 the force of gravity decreases as the square of the
 
 ASTRONOMY. 15 
 
 distance increases. The denser parts of the earth are 
 drawn by the attraction of the moon, and the water 
 being drawn with less force, causes the tide on the 
 opposite surface. 
 
 The tides are therefore always highest when the 
 sun and moon are in opposition, and when in con- 
 junction, or on the same side. 
 
 When they are in quadrature, or attracting at right 
 angles, the tides are lower. So they are highest when 
 the moon is new, and when she is in her third quarter. 
 
 As all the water on the globe comes under the 
 influence of the moon twice during the twenty-four 
 hours, it causes two tides during that time. 
 
 High water, therefore, occurs about fifty minutes 
 later one day than that of the previous day. 
 
 The tides are not of equal height in all places. In 
 the Bristol Channel the average rise is sixty feet. In 
 the Bay of Fundy, and in St. Malo Bay, it often rises 
 to a height of one hundred feet, while at places more 
 sheltered it does not rise above ten or fifteen feet. 
 
 Eclipses. When the moon, in its monthly revolu- 
 tion round the 
 earth, comes ex- 
 actly between that 
 planet and the sun, 
 
 it intercepts part ^ __^_ - 
 of the sun's light. ^^^^"^ \ 
 
 This is called solar 
 eclipse, or a con- 
 cealment, and the Flg- 8- 
 earth, moon, and sun, are in the same straight line. 
 Fig. 6. The solid body of the moon hides a part of 
 the sun from the inhabitants of the earth who happen 
 to be on the same side. Sometimes the surface of 
 the sun is entirely hidden, this is a total eclipse ; at 
 other times it is covered except a small ring round the 
 
 22
 
 16 OUTLINES OF SCIENCE. 
 
 outside of the moon, this is called an annular eclipse, 
 from annulus, a ring ; at other times only a part of 
 the sun is hidden, which is called a partial eclipse. 
 A solar eclipse can happen only when the moon is 
 either very old or very new. 
 
 A lunar eclipse can only take place when the moon 
 is full, or nearly so, be- 
 cause then only does the 
 earth lie between the sun 
 and moon, so as to allow 
 its shadow to fall upon 
 the moon. Fig. 7. 
 
 Both solar and lunar 
 eclipses would happen 
 every month, if the orbit 
 of the moon were in the same plane with that of the 
 earth. This is not so, but it makes an angle of about 
 5 degrees, with the plane of the orbit of the earth, 
 aud crosses it in two points called nodes. 
 
 To understand this, take two hoops, one a little 
 less than the other, place the smaller inside the larger 
 and open them a little ; you have then a picture of 
 the two orbits and their nodes. It is only when the 
 moon passes through these nodes that an eclipse can 
 occur, and this happens about four times a year, so 
 that we have two Solar and two Lunar eclipses on the 
 average. 
 
 An eclipse of the sun begins at the western side of 
 his disc, but an eclipse of the moon begins at the 
 eastern side of that planet. 
 
 By lunar eclipses we prove that the earth is a round 
 body, that the earth is greater than the moon, and 
 that the sun is greater than either. We also learn 
 how long it takes the moon to complete its circles 
 round the earth. 
 
 QUESTIONS ON CHAPTER IV. 
 
 What is longitude ? "What is the circumference of the earth.? 
 How many degrees does the sun pass over in one hour?
 
 ASTRONOMY. 17 
 
 WTiat is a great circle P How is time kept at sea ? 
 
 If a captain finds the sun in his meridian at two o'clock by his 
 
 chronometer, what will be his longitude ? If at nine 
 
 o'clock A.M. ? 
 
 Who perfected the chronometer ? What proof was> given of it ? 
 What is latitude ? What help is needed to find it ? 
 How often do the tides ebb and flow ? What do they seem to 
 
 follow ? 
 
 "Where are the tides highest ? When are they highest ? 
 In what places do very high tides occur ? To what height ? 
 What is an eclipse ? When does a solar eclipse happen ? 
 What is an annular eclipse ? j 
 
 When only can a lunar eclipse occur ? 
 Why does not a lunar eclipse happen every month ? 
 On which side does a solar eclipse occur ? 
 How often do eclipses happen in the year? 
 What do we learn from the earth's shadow on the moon ? 
 
 CHAPTER V. 
 
 THE MOON. 
 
 Form and Size. The moon is a globe similar to 
 the earth, but much smaller, as its diameter is only 
 about one-fourth that of the earth. It is distant from 
 us about 240,000 miles. The difference in the dis- 
 tance of the sun and moon from our earth will account 
 for the little apparent difference in their size, for 
 while the diameter of the sun is really 400 times that 
 of the moon, one seems nearly as large as the other. 
 The earth is forty-nine times larger than the moon. 
 
 The moon always shows the same face to us, though 
 it is certain that she revolves on her own axis slowly, 
 and so as to complete the revolution in about a 
 month. 
 
 From its comparative nearness to us, we know 
 something of its general appearance. It seems to be 
 covered over with hollow craters or cups, which are 
 
 23
 
 18 
 
 OUTLINES OF SCIENCE. 
 
 believed to be empty volcanoes. It does not appear 
 to have any atmosphere, like that of the earth and 
 the sun, nor is there any sign of water. 
 
 Half of it is always in the light, just as the earth 
 is, and no doubt the earth appears to the inhabitants 
 of the moon, if there be any, just as the moon appears 
 to us, and it affords to them the same help with its 
 reflected light. 
 
 Phases of the Moon. By Fig. 8, it will be easily 
 
 seen how the moon 
 passes through its 
 various phases or ap- 
 pearances in its pas- 
 sage round the earth. 
 When the moon is at 
 A, it is between the 
 sun and earth, and its 
 dark side is turned 
 to us. It is only 
 when it reaches B, 
 that wo see a small 
 part of the lighted 
 surface in form of a 
 Fls ' 8 ' crescent or horn, 
 
 which we call new moon. At C we see the half 
 moon, and its lighted surface continues to widen until 
 it reaches D, when it is full moon, after which it 
 grows gradually less towards E, until it is lost sight 
 of again at A. We may often see the full moon 
 during the daytime, but it is always on the side of 
 the heavens opposite to the sun, that is, always at D. 
 
 Harvest Moon, &c. Y\ 7 hen speaking of the high 
 tides, it will be remembered that they were stated 
 to occur about fifty minutes later each day. The 
 moon rises, as it is called, about so much later 
 every day, because when the world has gone its daily
 
 ASTRONOMY. 19 
 
 round, the same meridian will not be opposite the 
 moon, because the moon has been also moving on in 
 its monthly course. By a singular concurrence of 
 events, the moon at one season rises at shorter inter- 
 vals for several days together, than during the rest of 
 the year. This occurs at the end of August and part 
 of September, Avhen the fruits of the earth are being 
 gathered, and it is therefore called the Harvest Moon. 
 It is a great blessing, because the light is very much 
 prolonged by the moonlight commencing before the 
 daylight has ended. 
 
 The Winter Moon. In winter the northern hemi- 
 sphere is turned away from the sun (See Fig. 3), and 
 leans toward the full moon ; the moon has therefore 
 a greater altitude as compared with the earth, and 
 consequently shines longer and brighter. By this 
 means we have more moonlight in winter than in 
 summer, because in summer the northern hemisphere 
 is turned toward the sun, and the moon does not 
 reach so high an altitude above the horizon. 
 
 Easter Moon. It has long been settled among 
 Christians that " Easter Sunday is the first Sunday 
 after the full moon Avhich happens on or next after 
 the 21st of March." It is on this account that Easter 
 occurs later on one year than another. 
 
 THE STJN. 
 
 By observing the spots on the disc or face of the 
 sun, astronomers have ascertained that it revolves on 
 its own axis from west to east in about twenty-five 
 days. 
 
 Its diameter is about 107 times that of the earth, 
 and its bulk in comparison as 1,250,000 to one, so 
 that his bulk or volume is many times greater than 
 all the other planets put together. 
 
 To give some idea of the distance of the sun from
 
 20 OUTLINES OF SCIENCE. 
 
 us, it is said that if a cannon ball were fired at an 
 even velocity of sixteen feet in a second, it would 
 take nearly ten years to reach that great luminary. 
 
 Amount of Heat. Many speculations have been 
 made about the probable cause of the sun's heat. 
 Some have guessed it to be a ball of fire ; but if it 
 were of consumable matter, it must have long since 
 burnt itself out. Others have imagined its heat to be 
 caused by incessant striking of meteoric bodies on its 
 surface ; but the real cause is quite unsettled. 
 
 Although the earth receives a comparatively small 
 portion of its heat, it is estimated that the amount 
 received yearly would melt 100 feet thick of ice, or 
 boil sixty-six feet deep of water all over the globe. 
 
 Some philosophers say that " all force is heat" from 
 the steam which George Stephenson called "the sun's 
 heat bottled up" to the strength in man which is 
 needed for the smallest amount of labour. 
 
 Latent Heat. Much of the heat of the sun is 
 called latent, or hidden, because it is only developed 
 by friction, or some other force. 
 
 There is latent heat in ice ; for it requires nearly 
 as much heat to melt the ice to ice-cold water, as it 
 does afterwards to raise the water to the boiling 
 point, 212. The familiar case of making buttons or 
 other pieces of metal hot by rubbing them, is well- 
 known to every school-boy, and that is an example 
 of the development of latent heat. By this process 
 of friction pieces of dry wood are kindled by savages, 
 and the axles of wheels become red-hot if left un- 
 greased. 
 
 QUESTIONS ON CHAPTEE V. 
 
 "What is the size of the moon as compared with the earth ) 
 Give some description of the moon's appearance. 
 "Where is the moon, when its dark side is turned to us ?
 
 ASTRONOMY. 21 
 
 Where ia the moon when we see her at the full? 
 
 How much later each day does the moon rise ? 
 
 What other phenomenon is similar to this ? 
 
 When does the harvest moon occur ? 
 
 When have we the most moonlight ? Why ? 
 
 What relation has Easter to the moon ? 
 
 How do we know that the sun turns on hia axis ? 
 
 What is his distance from the earth ? 
 
 Why cannot the sun be a body of fire ? 
 
 What did Stephenson call steam ? 
 
 What is latent heat ? Where is it found ? 
 
 Give instances of developing latent heat. 
 
 CHAPTER VI. 
 
 THE PLANETS, 
 
 Mercury, $ . When the astronomers of old 
 watched the heavenly bodies, they noticed that some 
 of the large ones did not always keep the same posi- 
 tions as they found the fixed stars to do. They 
 therefore called them planets or wanderers. 
 
 The planet Mercury is the smallest, and is nearest 
 the sun in the Solar System, being distant about 
 35,000,000 miles, and going round him in eighty- 
 eight days. 
 
 The nearer the sun, the faster a planet moves, so 
 that the rate of travelling of Mercury through space 
 is 105,000 miles an hour, while that of the earth is 
 66,000. The diameter of Mercury is about 3,000 
 miles, and he is so close to the sun that he can never 
 be seen except in twilight, that is just before sun- 
 rise, or just after sunset. 
 
 Transits of Mercury, or passages across the disc of 
 the sun, which occur about once in ten years on an 
 average, show that he is an opaque body like the
 
 22 OUTLINES OF SCIENCE. 
 
 earth, and has phases like those of the moon, which 
 vary with his position. 
 
 Venus, ? .This planet is 66,000,000 miles from 
 the sun, and has a diameter of 7896 miles. She goes 
 round the sun in 225 days, and seems to be some- 
 times larger than at other times. The axis of Venus 
 is more inclined than that of the earth, and there- 
 fore there must be a greater variety in the seasons. 
 Her transit only happens once in about sixty years. 
 We see much more of this beautiful planet than of 
 Mercury, as a morning or evening star. When west 
 of the sun she appears a morning star, and when east 
 of him an evening star. 
 
 Next to Venus is the Earth, 0, which has been 
 more fully noticed elsewhere. 
 
 Mars, cf . Beyond the earth, that is, outside of it 
 from the sun, the next planet is Mars. His distance 
 from the sun is about 139,000,000 miles, his diameter 
 only 4,175 miles, about half that of the earth, and 
 his year about 687 days, or not quite two of our 
 years. The diameter of Mars appears greater to us 
 because his distance from us is only 48,000,000 miles, 
 and we are able to see him with greater ease. His 
 daily revolution is known by a large and very re- 
 markable spot on his disc. He may be readily dis- 
 tinguished by his red appearance, from which the 
 ancients named him after Mars, their god of war. 
 
 The Asteroids, or little stars, are most of them 
 very small, and are contained in the great space of 
 the Solar System, between Mars and Jupiter. They 
 amount to eighty in number, and the largest is only 
 about y^g- part of our moon, while the smallest is not 
 Wge enough to be measured. The reasonable opinion 
 of astronomers is, that they once formed one planet, 
 which by some extraordinary explosion or convulsion 
 has been blown to pieces.
 
 ASTRONOMY. 23 
 
 Jupiter, I/ . This planet is distant from the sun 
 490,000,000 miles, and is 1,240 times larger than the 
 earth ; his diameter is about one-tenth of that of the 
 sun, while Jupiter's is eleven times that of the earth. 
 His year or revolution round the sun takes nearly 
 twelve years, but his day is not quite ten hours. 
 This very rapid diurnal rotation causes the equa- 
 torial regions to bulge out, so that there is believed to 
 be a difference of 6,000 miles between the polar and 
 the equatorial diameters. The axis of Jupiter is per- 
 pendicular to his orbit, and not inclined, as in most 
 other of the planets. 
 
 Jupiter has four satellites or moons of large size, 
 which are easy of observation. The largest of these 
 is half the size of the earth, that is about equal in 
 size to Mars, two others are one-third, and the 
 smallest one-fourth the size of the earth. He has 
 also dark streaks across his disc called belts, which 
 vary in size at different times, and are supposed to be 
 his atmosphere in his various conditions of quiet or 
 excitement. 
 
 The moons of Jupiter afford valuable help in mea- 
 suring the velocity or swiftness of light. It is found 
 that when Jupiter is on the same side of the sun that 
 the earth is, astronomers see his moons emerge from 
 their eclipses seventeen minutes earlier than when the 
 earth and Jupiter are on opposite sides of the sun. 
 Light therefore must travel across the intermediate 
 space of nearly 190,000,000 miles during that time, 
 which gives the wonderful velocity of 192,000 miles 
 in a second. 
 
 This remarkable circumstance first attracted the 
 notice of the famous Galileo, the Italian astronomer, 
 who was imprisoned by the Inquisition because he 
 asserted that the world moved.
 
 24 
 
 OUTLINES OF SCIENCE. 
 
 QUESTIONS ON CHAPTEK VI. 
 
 What planet is nearest to the sun ? 
 
 Why were some heavenly bodies called planets ? 
 
 At what rate must Mercury travel ? 
 
 When only can he be seen ? and why ? 
 
 How do we know that Mercury is an opaque body ? 
 
 What is the distance of Venus from the sun ? 
 
 What is the length of her year ? 
 
 Why must there be a great variety in her seasons ? 
 
 When does Venus appear a morning star ? 
 
 Between which planets is the earth ? 
 
 What is the distance of Mars from the sun ? 
 
 What is his distance from the earth ? His year ? 
 
 How may Mars be easily known ? 
 
 What are found between Mars and Jupiter ? 
 
 How many are known to exist ? 
 
 What is the size of Jupiter as compared with the earth ? 
 
 The length of his day ? And of his year? 
 
 What is peculiar about his diameter ? 
 
 How many moons has Jupiter ? 
 
 At what rate does light travel ? How is this known ? 
 
 CHAPTEE VII. 
 
 THE PLANETS Continued. 
 
 Saturn, ^ - This planet is nearly as large as 
 
 Jupiter, having 
 a diameter of 
 73,800 miles. His 
 mean distance 
 from the sun is 
 871,000,000miles, 
 his year is nearly 
 as long as thirty 
 
 
 of ours, while his day is only about 10 hours. 
 
 _ Saturn has eight moons, besides two, if not three 
 
 rings, which can only be seen from the earth, when
 
 ASTRONOMY. 25 
 
 he is elevated above the orbit of that planet. These 
 rings are believed to revolve round the planet, and 
 the largest of the moons turns on its own axis, as 
 our moon does. 
 
 TTranus, fij[, also called Herschel. The next planet, 
 called Uranus, was discovered by Dr. Herschel, in 
 1781, and formerly called Georgium Sidus, or George's 
 Star, in honour of King George III., who was the 
 great friend and patron of Herschel. 
 
 This planet is 1,800,000,000 of miles from the sun. 
 His year is equal to eighty-four of ours, and he is 
 about eighty tunes greater than the earth. Uranus 
 has several moons, but their number is not yet accu- 
 rately known. They revolve in a different direction 
 round the primary planet, from all other planets and 
 moons that is, around ii^Q polar instead of the equa- 
 torial circumference. 
 
 Neptune, CJ2 . This planet, which is the most dis- 
 tant of all at present known to astronomers, was 
 discovered by Mr. Adams, in 1845, and shortly after- 
 wards by M. Le Verrier, a French astronomer. The 
 new planet is 2,473,000,000 of miles from the sun, 
 and his year is equal to 165 of ours. He is thought 
 to be a little larger than Uranus. At present only 
 one of his satellites has been discovered, but there 
 are doubtless several others. 
 
 Lately, the French astronomers have spoken of 
 another new planet only 14,000,000 of miles from the 
 sun, but at present the fact of its existence is not 
 ascertained. It is to be named Vulcan, if it is proved 
 to be a planet. 
 
 Comets. These are hairy-looking luminous 
 bodies connected with the Solar System, about which 
 very little is known, but whose appearance in former 
 times threw the people of the world into a great 
 fright. They move in what are called eccentric 
 
 3
 
 26 OUTLINES OF SCIENCE. 
 
 ellipses, and their periods of revolution, or of re-ap- 
 pearance, are very little known. 
 
 Though more than one hundred have been noticed, 
 only a few have appeared more than once, and these 
 at very long intervals, being at one time compara- 
 tively close to the sun, and then passing beyond the 
 reach of the most powerful telescopes. Nothing is 
 known of their composition, but they cannot be very 
 solid, as the fixed stars and planets have been seen 
 through the gauze-like tail and through the nucleus 
 or head of the comet. 
 
 Some approach the sun rapidly, and others at a 
 slow rate; some have several tails, but most of them 
 have only one. Only three have settled revolutions 
 and re-appearances ; those are Halley's, Encke's, and 
 Biela's comets. Halley's comet returns every seventy- 
 five years, Encke's in about three and a-third years, 
 and Biela's in about six years and eight months. 
 
 Fixed Stars. These are heavenly bodies so far 
 beyond the Solar System, that they cannot be mag- 
 nified by the most powerful telescopes. Unlike the 
 planets, which shine with a borrowed or reflected 
 light, each star shines by its own light, and since they 
 are at so vast a distance, they are supposed to be each 
 a centre of some planetary system, similar to ours. 
 
 Though not more than 16,000 stars can be seen 
 with the unassisted eye, there are supposed to be 
 vast numbers of them. 150,000 have been registered, 
 and Sir W. Herschel said that 50,000 passed his great 
 telescope in one hour. Some are in pairs, others in 
 threes, which revolve round each other, and in some 
 parts of the heavens they are so numerous as to form 
 star-clouds, or nebulae, like the Milky Way. 
 
 The Milky Way. This is the great luminous 
 band which stretches every evening all across the 
 sky.
 
 ASTRONOMY. 27 
 
 It is divided in one part of its course, sending off a 
 kind of branch, which joins the main body again. 
 
 This remarkable belt, when examined through a 
 telescope, is found to consist of millions of stars, which 
 are scattered like dust over the vast heavens. 
 
 QUESTIONS ON CHAPTER VII. 
 
 What is the diameter of Saturn ? 
 
 Give the length of Saturn's day and year. 
 
 How *s the planet easily known ? 
 
 How many moons ? and rings ? 
 
 What planet is outside of Saturn ? 
 
 By whom was he discovered ? What was he called ? 
 
 What is the year of Uranus ? His distance from the sun ? 
 
 What is peculiar about the moons of Uranus ? 
 
 When and by whom was Neptune discovered ? 
 
 What is his distance from the sun ? Length of his year ? 
 
 Where do French astronomers think there is another planet? 
 
 By what name is it to be known when discovered ? 
 
 What are comets ? How do they move ? 
 
 How many have settled appearances ? When ? 
 
 How can a fixed star be distinguished from a planet ? 
 
 What are the Nebulae supposed to be ? 
 
 Describe the Milky Way. 
 
 Of what is it found to consist ?
 
 28 OUTLINES OF SCIENCE. 
 
 BOTANY. 
 
 CHAPTER VIII. 
 
 BOTANY (from Borav?j, a plant) is the science which 
 treats of the structure and properties of the vege- 
 table kingdom ; from the largest tree, to the tiny 
 xnoss or seaweed. 
 
 Plants, as well as animals, are provided with organs 
 which are necessary to their existence, and which 
 answer to the various means with which the latter 
 are supplied. They choose food and reject it, they 
 breathe and perspire, they sleep, and have a circulat- 
 ing fluid. 
 
 Plants differ from animals in this respect, that they 
 feed on inorganic substances, such as minerals, water, 
 and air, while animals are supported chiefly by 
 organic substances ; so that plants live on minerals, 
 and animals are nourished by plants and vege- 
 tables. 
 
 Structural Botany is that part of the science which 
 describes the elementary organs of the plant, such as 
 the root, the stem or axis, the leaves, the flower, the 
 fruit, and the seed. 
 
 Of these the root, stem, and leaves feed the plant, 
 and are called organs of nutrition, while the flower, 
 fruit, and seed are called organs of reproduction, 
 because by their agency the new plant is generally 
 produced. We say generally, because plants are often
 
 BOTANY. 
 
 29 
 
 propagated by slips and cuttings, or by dividing the 
 root, as well as by seeds. 
 
 Physiological Botany treats of the internal struc- 
 ture of the plants, the tissues of which, they are com- 
 posed, their food, mode of assimilating it, organs of 
 respiration and circulation. 
 
 Other branches of botany are Descriptive and Sys- 
 tematic ; our business is chiefly with the structure and 
 physiology of plants, about which botanists are 
 agreed. 
 
 Parts of a Plant. The root, or radicula (1), is the 
 organ which chiefly 
 supplies the plant 
 with food. This is 
 either water, or some- 
 thing held in solu- 
 tion by water ; the 
 root is therefore 
 generally buried in 
 the earth, where the 
 moisture is found. 
 The root will strike 
 downward, even 
 though the seed may 
 be intentionally 
 placed the wrong 
 way up. 
 
 The root never 
 produces buds, and 
 in small plants is 
 usually of a white or 
 pale colour, because it is hidden from the light. 
 
 On examining carefully the root of the common 
 buttercup, or heart's-ease, for example, we find that 
 the roots grow gradually smaller like threads, and at 
 the end of each rootlet there is a small tnft. 
 
 33 
 
 Fig. 10.
 
 30 OUTLINES OF SCIENCE. 
 
 If this be cut off, split up, and placed under a 
 microscope, or a good glass, it will be seen that the 
 end of it is covered with a little sheath, and the part 
 which is thus covered or protected is the growing 
 point of the root, which is constantly extending itself 
 in search of food, through the rough hard soil into 
 fresh places. This sheath is fed from the inside by 
 the little growing point which it protects. 
 
 The stem or candex (2) begins where the proper 
 root ends. It is usually coloured green ; and bears 
 foliage leaves on each side of it of numerous forms 
 and variously situated or arranged, sometimes oppo- 
 site to each other, sometimes alternate. From the 
 lower leaf-joints, called nodes, smaller stems usually 
 spring, and the stem gradually grows more slender 
 until it reaches the flower. The flower-stalk is called 
 a peduncle (3), at the end of which is the receptacle (4), 
 of a colour similar to the stem. 
 
 Inside the receptacle are other green leaves called 
 the sepals, and together the calyx, (4) or flower-cup, and 
 within them coloured leaves, which form its chief 
 beauty, and are called the corolla (5). The calyx and 
 corolla are composed of several separate parts, which 
 vary in number according to the class to which the 
 flower belongs. Inside the flower are found a num- 
 ber of small steins or stamens (6), on the end of 
 which there is to be seen a kind of dust called 
 pollen, and usually in the centre of the stamens, 
 there is one or more longer than the rest, and some- 
 what different in form, which is called the pistil (7). 
 This is hollow, and at its base is situated the seed- 
 vessel (8). 
 
 Before the seed can be formed, the pollen must be 
 passed from the stamens down the centre of the pistil, 
 where it gradually expands and assumes its proper 
 form, the leaves of both calyx and corolla fall off, and
 
 BOTANT. 31 
 
 the seed-vessel having ripened in the heat of the sun, 
 bursts and allows the ripe seed to escape on to the 
 ground, unless preserved by artificial means. 
 
 Thus we have the root, stem, leaves, peduncle, 
 receptacle, calyx, corolla, stamens, pistil, and seed- 
 vessel, all of which perform an important part in the 
 production of the fruit. \^. 
 
 Varieties of Root These are (1) the tap or pivot 
 root, which is long, taper, and simple, like the carrot, 
 parsnip, and beet-root, or is globular like the turnip 
 and bulbous ranunculus. 
 
 (2). Branched roots, in which, added to one prin- 
 cipal root, there are others branching from it, as in 
 most large trees and shrubs. 
 
 (3). Fibrous roots, consisting of long fibres, some 
 very thin and fine, such as wheat, barley, and the 
 other grasses. Roots vary somewhat according to 
 the soil or position in which they are found, and it is 
 remarkable that nearly all become fibrous when 
 exposed to the action of running water. 
 
 (4). Bulbous roots, such as the onion, hyacinth, 
 lily, &c. 
 
 There are some varieties which do not belong to 
 any of the above. For example, the misletoe, and 
 many lichens, which are called parasitical plants, 
 because they fix their roots into other plants, instead 
 of the ground, and appear to live on their juices. 
 
 There are also some roots which are called adventi- 
 tious. These form creeping stems, which give off root 
 fibres at the nodes, and which extend in this manner 
 over a large space. Familiar examples of this are to 
 be found in the common garden mint, and in the 
 campanula. 
 
 In perennial herbaceous plants like the dahlia, the 
 root thickens in the ground, and so becomes a rest r- 
 voir of nutritive matter, which is thereby stored up
 
 32 OUTLINES OF SCIENCE. 
 
 during winter until required to nourish the young 
 shoots of the coming spring. 
 
 As proper roots never give off stems, we must 
 remember that the potato and other similar plants, 
 from the eyes of which come the new shoots, are not 
 roots, but only thickened portions of the stem, the 
 potato root being quite separate. 
 
 QUESTIONS ON CHAPTER VIII. 
 
 What is Botany ? How are plants like animals ? 
 
 In what respect do they differ from them ? 
 
 What is structural botany ? 
 
 Name the organs of nutrition and of reproduction. 
 
 Of what does physiological botany treat ? 
 
 How is a plant chiefly fed ? What ia said of the root P^, 
 
 What is found at the end of the root ? How is it coTered T 
 
 Name the other parts of the plant. 
 
 What are the various kinds of root ? 
 
 Name some fibrous root. Some bulbous. 
 
 What are parasitical plants ? 
 
 What are adventitious roots ? Name some. 
 
 What is the advantage of the thick dahlia root ? 
 
 Is the potato a root ? What is it ? 
 
 CHAP TEE IX. 
 
 The Leaf and its Functions. Leaves, as said else- 
 where, assume very many forms, in different plants. 
 Sometimes the leaf-stalk is wanting, and then the 
 broad leaf, or lamina, adheres closely to the stem, and 
 is called sessile, as in woodmint, sowthistle, and others. 
 In other cases there are several produced from points 
 forming a ring on the stem, which is called a whorl or 
 verticil. Examples of this are seen in goose-grass, 
 and mare's-tail. Others are pinnate, like the rose leaf, 
 entire like laurel and lilac, serrated or notched like the 
 nettle, sinuated like the oak-leaf, &c.
 
 BOTANY. 33 
 
 Whatever their form, they all have the same duty 
 to perform. As the root is the organ of absorption, 
 by which nourishment may be said to be sucked up 
 from the soil, so the stem is the conducting medium 
 of that nourishment, while the leaves are organs of 
 transpiration, assimilation, and respiration. 
 
 Transpiration. If fresh leaves be soaked in water, 
 in the summer, and placed under glass in the sun, 
 there will be a quantity of oxygen evolved, which 
 can be collected and experimented upon ; this giving 
 out of oxygen, which has been received probably 
 in the form of carbonic acid, is called transpiration. 
 
 Assimilation. To receive it as carbonic acid, and 
 to separate the oxygen so as to evolve it, as just 
 mentioned, using the carbon for growth and nourish- 
 ment, shows a function of the leaf which is called 
 assimilation. 
 
 Respiration. It is also known that the green parts 
 of plants, in the night, or in dark places, absorb 
 oxygen, and give off carbonic acid, and this process 
 of drawing in oxygen is called respiration or breath- 
 ing. Hence it is considered unhealthy to keep plants 
 in a sleeping-room during the night, because carbonic 
 acid in excess is injurious to human life. 
 
 Analysis. By burning a plant, and analysing the 
 ashes, it is found to contain various minerals, the 
 chief of which are sulphur, soda, potash, phosphorus, 
 lime, silex, and others, in small quantities, of course, 
 and not all in the same plant, but sufficient to show 
 that these substances have been absorbed by the 
 roots. Silex, which is the basis of flint, is found in 
 the stalks of Avheat, bamboo, and all other grass 
 plants, and in the teak, and other hard woods. 
 
 Food of Plants. The organic matter of mould, 
 consisting of decayed vegetables, &c., is continually 
 forming carbonic acid. This is intended to be
 
 34 OUTLINES OF SCIENCE. 
 
 absorbed by plants with water, which is the chief 
 medium through which they are fed. They also 
 absorb nitrogen, and some kinds, if planted in pure 
 sand, will increase in their per centage of nitrogen, 
 which must therefore be derived from the atmosphere. 
 Those plants which have the largest leaves are 
 found to be less exhaustive and injurious to the 
 ground, as they derive so much of their nourishment 
 from the atmosphere. This is the case with turnip, 
 beet-root, and other large-leaved plants. 
 
 Air necessary. Plants, like animals, must have 
 air. If either a plant or seed be placed in the ex- 
 hausted receiver of an air-pump, it will not grow, 
 even though the mould in which it is planted is of 
 the richest and most suitable character. No other 
 gases besides those which form air, in their present 
 combination, are suited to nourish plants; most of 
 them are highly injurious, and cyanogen utterly 
 destructive. Both leaves and roots require air, hence 
 the advantage of frequently ploughing or otherwise 
 disturbing the soil. 
 
 Fruit. Until fruit is nearly ripe, it feeds on the 
 atmosphere, as the leaves do. The young apple, 
 when hard and almost tasteless, contains only woody 
 fibre and starch, but as it grows it absorbs oxygen in 
 definite proportions, and contains in succession tar- 
 taric acid, malic acid, and subsequently sugar. 
 
 Light. This is necessary to the plant, but inju- 
 rious to the seed, which germinates best when con- 
 cealed from light. Sugar is also formed more rapidly 
 in beet-roots and other plants, when the root is partly 
 hidden by large leaves. Celery roots, if uncovered, 
 would be bitter instead of sweet, and contain much 
 less sugar. One result of abundant sunlight and heat 
 is seen in the fact that the sweetest and most 
 aromatic plants are found in warm countries.
 
 BOTANY. 35 
 
 Design. It is especially worthy of notice, as a 
 wise design in creation, that plants live upon an ele- 
 ment, or part of it, which is injurious to man, 
 namely, carbonic acid, and that having, as just shown, 
 separated the carbon and used it, it transpires or 
 breathes out the oxygen, which gives life and energy 
 to man and other animals. 
 
 Irritability. One peculiar property of leaves is 
 seen in their power of closing or of moving, under 
 the influence of weather, sunlight, atmospheric pres- 
 sure, or the touch of any foreign object. Many 
 plants close in the night, or, as Linnaeus said, " they 
 sleep." The leaves of the Acacia and many others, 
 droop as night approaches, and revive when morning 
 appears. 
 
 More striking examples are those of the Dionoea 
 and the Mimosa pudica, or sensitive plant, the leaves 
 of which close in pairs, the instant that plant is 
 touched, until, if the touches be repeated, the whole 
 leaf droops as if dying, and only revives after some 
 time has passed. The Dioncea, or Venus fly-trap, a 
 North American plant, has leaves which close sud- 
 denly when an insect lights upon the stiff prickly 
 hairs with which their insides are covered, and kill 
 the prisoner. The sun-dew, common in English 
 marshes, has a similar property, but in a less 
 degree. 
 
 Plants require sun-light to flourish, so that if put 
 in a cellar with a small opening, the leaves will all 
 turn their upper sides toward the opening, and the 
 stalks will grow longer as if by stretching. The 
 leaves of most plants fall off in cold climates ; those 
 which are evergreen, such as fir, pine, larch, and 
 others, have peculiar fluids in their bark or skin, 
 which defend them from the weather. 
 
 Those which lose their leaves are called deciduous,
 
 36 OUTLINES OF SCIENCE. 
 
 and some which lose their leaves in cold climates, 
 retain them in their native climes, such as the orange, 
 oleander, and others. 
 
 Design may also be seen in the cotyledons or first 
 leaves of a plant, which are usually larger and more 
 fleshy than later leaves. They serve as protectors to 
 the little germ, until it is strong enough to do with- 
 out them, when they fade or die off the little plant. 
 Familiar examples are seen in garden beans and peas. 
 
 QUESTIONS ON CHAPTER IX. 
 
 What is the function of the leaf? 
 Name some principal kinds of leaf. 
 What example is given of transpiration ? 
 What is called assimilation in plants ? 
 What is exhaled by plants during the night ? 
 What minerals are commonly found in plants P 
 What articles form their principal food ? 
 Prove that they receive nourishment from air. 
 What happens to a plant in an air-pump ? 
 What is the advantage of ploughing the earth? 
 What are the components of a hard apple ? 
 'What does it absorb as it ripens ? 
 How is a plant affected by light ? 
 How do plants favourably affect the atmosphere P 
 What ig irritability ? Give some examples. 
 What more do plants require to flourish ? 
 Distinguish between deciduous and evergreen. 
 What is remarkable about the cotyledons ? 
 
 CHAPTER X. 
 
 The Bud. The bud consists of a collection of the 
 rudiments or commencement of leaves, surrounding a 
 central vital point. It may be a leaf-bud, or a flower- 
 bud ; leaf-buds are seen in autumn, as they are pro- 
 duced in the axilla or centre of the leaf, and therefore 
 appear when the leaf falls off. They are generally
 
 BOTANY. 37 
 
 covered with thick leaves or scales, called perules, 
 which protect them from the weather, and sometimes 
 they are also coated with a resinous matter which may 
 be best seen in the leaf-bud of the horse-chestnut. 
 
 Hairs and Glands. Many plants, especially those 
 which grow in exposed situations, have numerous 
 hairs scattered over the stem and leaves. These are 
 of two kinds, namely, the lymphatics, which are be- 
 lieved to regulate the escape of moisture by evapora- 
 tion, and the secreting hairs or glands, which contain 
 fluids peculiar to the plant. 
 
 Secretion. A familiar example of the secreting 
 gland is the hair on the stinging nettle, which, when 
 touched, pierces the skin, and a sharp acrid juice 
 flows into the wound from a little bag at the base of 
 each hair, which causes the tingling or smarting 
 pain. 
 
 It is believed that the perfume of plants and 
 flowers arises from the secretions contained in the 
 glands, which are most powerful when crushed. 
 
 The Flower. This, as we have shown, is composed 
 of several distinct portions, and is the most important 
 part of a plant, as it is the seed producer. The 
 flowering, or inflorescence, is various in form in different 
 flowers. Sometimes, as in the peony, one flower is 
 produced on one stem, and then ends ; this is called 
 solitary and terminal. 
 
 When all the buds on an axis become flowers, as in 
 the hyacinth, it is called a raceme. If they are also 
 sessile, as in corn, lavender, saintfoin, and many other 
 plants, they form a spike, so that an ear of corn is a 
 spike ; the catkin of the nut, filbert, walnut, and 
 other trees, are pendent because they hang down. 
 When many flowers are in a bunch, as in the carrot, 
 hemlock, celery, &c., each bunch is called an umbel, 
 and the bunches on one peduncle are called a com- 
 
 4
 
 38 OUTLINES OF SCIENCE. 
 
 pound umbel such plants are called umbelli- 
 ferous. 
 
 The Stamens. These are said to be the male 
 organs of a plant. At the top of a thin filament is a 
 small hollow case or sack, which is called an anther ; 
 this anther is filled with many minute globules called 
 the pollen, which contains a fluid. Shortly after the 
 expansion of the flower, the anther opens, and the 
 pollen is scattered on the pistil, which is the female 
 organ. This process is essential to the perfecting of 
 the seed, and has sometimes to be performed by the 
 hand, as in the cultivation of the cucumber. 
 
 The form of the stamens and pistil, with the 
 anthers, may be plainly seen in all the lily tribe. 
 Moreover, as these stamens have been made the basis 
 of a system of botany, they are especially worthy of 
 notice. High cultivation is very injurious to the pro- 
 ductiveness of plants, as it often converts the stamens 
 into petals, and makes the flower double. The anther 
 then disappears, and no seeds are produced. So we 
 never have seed from these double blossoms, or 
 flowers. 
 
 The Pistil. This usually consists of three parts, 
 the ovarium, or seed-vessel, at the base, the style, and 
 the stigma. When the pollen-fluid enters the stigma, 
 it is conveyed into the ovarium, which is variously 
 shaped, and often contains numerous cells or cavities, 
 like the poppy and passion-flower. Sometimes the 
 pistil is hidden as in the violet, and in other cases the 
 anthers and pistil will have the same style or stem. 
 
 When the anthers have deposited the pollen on the 
 pistil, their function ceases, and they, with the corolla, 
 die off ; but the pistil and ovarium continue to enlarge 
 and ripen until the seeds arrive at maturity, and fall, 
 or are collected to be resown. 
 
 Fruit, in botany, meaus the ripened ovarium ; it
 
 BOTANY. 39 
 
 may be a pea-shell, an apple, a strawberry, a marsh- 
 mallow cheese, or a simple flower-seed like the sweet- 
 william, or any ordinary annual. The ripe seed- 
 vessel is called the pericarp, the outer skin is the 
 epicarp, the pulp is the sarcocarp, and the stone or 
 inner shell is the endocarp ; only the kernel is the true 
 seed. 
 
 QUESTIONS ON CHAPTER X. 
 
 How are leaf-buds protected from the weather ? 
 What is the axilla ? When can it be seen ? 
 What is remarkable of the horse-chestnut leaf ? 
 What are lymphatics, and secreting glands ? 
 Give some common example of secreting glands. 
 What is said of the perfume of plants ? 
 In which part of the plant is the seed perfected ? 
 Give examples of a raceme, and of a spike. 
 Which are called the male organs of a plant ? 
 What is required to the perfecting of the seed ? 
 Name the various parts of the pistiL 
 What is meant by fruit in botany ? 
 Distinguish the pericarp, sarcocarp, and endocarp ? 
 What is the only true seed ? 
 
 CHAPTER XL 
 
 Vegetable Physiology. We have thus traced the 
 external form of the plant from its root to its ripened 
 fruit. We now proceed to notice its internal structure 
 and component parts, which are called the elementary 
 organs of the plant. All the parts which we have 
 mentioned, seem to be produced from the combination 
 of the elementary organs, membrane and fibre. 
 These are so fine as to require the use of powerful 
 magnifiers to detect the peculiarities of their forma- 
 tion. There are three principal forms in which mem- 
 brane and fibre are combined. In cellular tissue, 
 
 42
 
 40 OUTLINES OF SCIENCE. 
 
 elementary membrane, or woody fibre, and vascular 
 tissue. 
 
 On placing thin slips of pith, or what is better, a 
 small portion of garden rhubarb, which has been 
 slightly boiled, under a magnifier, it is found that it 
 is composed of a number of small cells or bags placed 
 side by side, and of very irregular formation. 
 
 Cellular Tissue. These hollow bags are filled with 
 fluid, and compose the cellular tissue which is found 
 in every part of a plant. Besides the little sacs, 
 there are to be seen very fine threads or filaments, and 
 these tubes contain a spiral thread still finer ; these 
 are called vessels. The pith of the alder shows a 
 similar arrangement of cells, but of an irregular form, 
 which is caused by pressure of the cells one upon 
 another. They are variously formed in other plants. 
 
 These cells thicken as they grow old, and cease to 
 help in the nourishment of the plant ; the cells are 
 then empty, and only the cell-walls remain. The 
 cell-walls are composed of carbon, oxygen, and 
 hydrogen ; whereas the cell-contents also contained 
 nitrogen, in addition to the other three. The cells, 
 while living, increase by dividing, each separate cell 
 becoming two, in consequence of a division growing 
 up its centre ; so soon as this dividing tissue is com- 
 pleted, the cell separates into two. 
 
 Cell Contents. These cells contain various sub- 
 stances in different plants ; thus, in the potato the 
 cells are filled with tiny granules of potato starch ; 
 in many seeds they are filled with oils, in the sugar- 
 cane and beet-root they contain sugar. While the 
 potato is good, the starch is kept in store, but as 
 spring returns, the starch softens, and is used up or 
 fed upon by the young plant when germinating 
 
 The fibrous tissue is composed of longer cells 
 than the cellular tissue, generally much longer, and
 
 BOTANY. 41 
 
 growing narrower at each end. As these grow old, 
 their sides thicken and become hard, and form the 
 wood of the plant. 
 
 The Stem and Sap. The stems of plants are 
 divided into two classes : those which grow externally, 
 and are called exogenous or dicotyledous, such as are 
 usually found in temperate regions, and those which 
 grow internally, and are called endogenous, such as the 
 date, and other palms, cocoa-nut, sugar-cane, and most 
 other trees in tropical climates. They are also called 
 monocotyledons. 
 
 Endogenous trees have no real bark, from the pecu- 
 liarity of their growth. A hollow stem shoots up, 
 and within this hollow, layer after layer of inner lark 
 is deposited, until the trunk becomes a solid mass, 
 and can grow no larger. The result is extreme hard- 
 ness of the outer bark, a familiar example of which is 
 the common cane. 
 
 Exogenous trees, like those which we see every- 
 where around us, are more complicated in form. 
 While the wood grows from outside, the bark is 
 endogenous, and grows from within ; as the wood 
 increases outwardly layer by layer, and year by year, 
 the bark increases in a similar manner from within. 
 As the inner coats of bark press upon the outer, it 
 cracks and becomes rough, as we commonly see it in 
 our bushes, shrubs, and trees. 
 
 The exogens are called dicotyledons, because they 
 are all produced from a seed which has two cotyledons, 
 or fleshy lobes, such as may be seen in the pea, bean, 
 acorn, and other seeds. 
 
 The Pith. If the stem of a dicotyledonous tree be 
 cut across, it will be found to consist of the following 
 parts. The pith, the medullary heath, the wood 
 and the bark. In herbaceous plants, the pith occu- 
 pies the greater part of the stem, also in some rapid
 
 42 OUTLINES OF SCIENCE. 
 
 growers like the alder ; but in old trees, its cells 
 are thickened or filled up, so as to differ very little 
 from the wood. 
 
 The Sheath. The medullary sheath surrounds the 
 pith, and is a tissue of spiral vessels and 
 ducts, which carry water and other 
 nutriment from the root to the leaves, 
 with which it has a direct communi- 
 cation, and in which the food under- 
 goes various changes, as noticed else- 
 where. 
 
 * The Wood. Next comes the wood, 
 
 which is seen to be in rings in any plant which is more 
 than two years old. By these rings the age of the 
 tree may be generally known, as a new ring is added 
 each year. It is worthy of notice that some tropical 
 trees shed their leaves oftener than once a year, and 
 form a ring each time, so that in such cases the age of 
 the tree cannot be so easily ascertained. 
 
 Some sceptics, trusting to the number of rings, 
 have tried to show that there are living specimens of 
 tropical trees, which date back beyond the Deluge. 
 These years should be reckoned as periods of vegeta- 
 tion, and not actual years, as would be the case in the 
 exogens of temperate climates. The layers nearest to 
 the centre are hardest, as the vessels are filled up 
 with the secreted juice turned to solid wood. For 
 this reason heart of oak, and other central wood, is 
 used where great durability is required. The outer 
 layers of wood are less hard, and are called alburnum, 
 and it is through this part of the tree that the sap 
 ascends from the root to the leaves. 
 
 The Bark. The inner part of the bark is called liber, 
 and is the source of new roots, buds, and leaves. 
 Hence it is that old trees often flourish, after the ripe 
 wood has been hollowed out. The epidermis, or outer 
 bark of the tree, is continually decaying or sheathing
 
 BOTANY. 43 
 
 off, after it has been cracked by the pressure of the 
 liber within, and the outer surface of the liber as con- 
 stantly supplies its place. 
 
 In the cork oak-tree of Spain and Portugal the 
 epidermis is very thi3k, and it is this 
 which furnishes the cork that is so 
 valuable to us. 
 
 Monocotyledons (see Fig. 12) are 
 easily distinguished from others ; if 
 one be cut across, a piece of cane, for 
 example, it will be seen that they 
 consist of bundles of woody fibres, Fig. 12. 
 and ducts or passages, dispersed among a mass of 
 lengthened cellular tissue, and crowded together 
 toward the outside. It increases by the formation of 
 successive new bundles of tissue in the centre of the 
 wood, and its diameter can never increase after the 
 epidermis becomes hard, hence the crowded state of 
 the outer ducts near the edge. 
 
 These little tubes give an example of capillary 
 attraction, as spirits of wine and other volatile fluids 
 will rise through them, if a short piece of cane be 
 dipped into the fluid. 
 
 QUESTIONS ON CHAPTER XL 
 What are the elements which compose plants ? 
 Of what is cellular tissue composed ? 
 In what plants may it be easily observed ? 
 Of what are the cells formed ? What do they contain ? 
 How are the stems of plants divided ? 
 What is an exogenous plant ? Give examples. 
 By what other names are exogens known ? 
 Name some examples of dicotyledons. 
 What is the medullary sheath ? what its duty ? 
 How may the age of an exogen be known ? 
 Which is the hardest part of the tree, and why ? 
 What is alburnum ? What is liber? 
 What is the epidermis ? What is cork ? 
 How do you distinguish the wood of an endogen ? 
 What example of Mpillary attraction is given?
 
 44 OUTLINES 07 SCIENCE. 
 
 CHAP TEE XIL 
 
 SYSTEMATIC BOTANY, OE CLASSIFICATION OF PLANTS. 
 
 THE first attempt at a classification of plants was 
 made in 1583 by Caesalpinus, an Italian, who divided 
 them into trees and herbs. The trees he arranged in 
 two classes, based upon the situation of the ovary or 
 seed-vessel, and the herbs into thirteen classes, also 
 agreeing with their seeds and seed-vessels. 
 
 He was followed and improved upon by Robert 
 Morrison, who was professor of botany at Oxford in 
 1660 ; but the most complete and philosophic method 
 for a long time, was that of John Eay, the eminent 
 English naturalist. 
 
 This method gave place to that of Linnaeus in 
 1738, which was very generally adopted, and remained 
 in vogue until Bernard de Jussieu, adopting the 
 primary divisions of Ray, laid the foundation of the 
 Natural System, which was perfected, or greatly im- 
 proved by his nephew, Antoine L. de Jussieu, and 
 which is still followed in France. 
 
 The system of Linnseus is very interesting. He 
 divided plants into twenty-four classes, each consisting 
 of two or more orders. The first eleven classes were 
 founded on the number of the stamens, and their 
 orders on the number of the pistils. 
 
 The twelfth contains plants with not more than 
 twenty perigynous stamens, the thirteenth those with 
 similar stamens, more than twenty in number. The 
 fourteenth and fifteenth made their orders to depend 
 on the form and structure of the fruit ; the sixteenth, 
 seventeenth, and eighteenth, made the orders to 
 depend on the number of the anthers, and so on to 
 the twenty-fourth, which comprised all flowerless or 
 cryptogamous plants.
 
 BOTANY. 45 
 
 THE NATURAL SYSTEM. 
 
 The Natural System, as somewhat modified by De 
 Candolle, begins with the highest forms of plants, and 
 descends to the lowest. Jussieu began in the oppo- 
 site direction, from low to high. 
 
 The vegetable kingdom admits of two great divi- 
 sions. 
 
 I. Flowering plants, called Phsenogamae, Cotyle- 
 doneae, or Vasculares. 
 
 II. Flowerless plants, called Cryptogamse, Acotyle- 
 donese, or Cellulares. 
 
 These are again divided into sub-divisions, classes, 
 and orders. 
 
 Division I. Flowering plants, or Phaenogams, sub- 
 divided into Exogens, or Dicotyledons, Endogens, 
 or Monocotyledons, and Rhizogens. 
 
 Exogens have embryo with two seed leaves, as 
 pea or bean ; stem increased by ex- 
 ternal layers, and leaves furnished 
 with a network of veins. (See 
 Fig. 13). 
 
 Endogens. Embryo with one or 
 many alternate seed leaves, stem in- F >e- 13 - 
 
 creased by internal growth of cellular tissue and fibre, 
 veins of the leaves running parallel, and flowers with 
 three, six, or nine petals. 
 
 Exogens, sub-divided into four classes. 
 
 Class I. Thalamiflorae, from thalamus, the receptacle, 
 including flowers that have calyx with separate 
 divisions, and corolla with distinct petals. Petals 
 and stamens inserted in the receptacle or 
 thalamus. Example The Eanunculus, or but- 
 tercup tribe, the poppy, cabbage, and many others.
 
 46 OUTLINES OF SCIENCE. 
 
 Class II. Calyciflorae, having petals and stamens in- 
 serted in the calyx. Examples the tea-tree, 
 cashew-nut, pea, bean, the broom, and many 
 other pod-bearers. 
 
 Class III. Corolliflorae, flowers having a corolla with 
 the petals united, and not inserted in the calyx. 
 Common examples Azalea, rhododendron, 
 heaths, &c. 
 
 Class IV. Monochlamydese, or Acorolliflorse flowers 
 without petals, and having only a single floral 
 envelope. Examples Marvel of Peru, the 
 cockscomb, love-lies-bleeding, beet-root, and 
 many others. 
 
 The Endogens, which include one-fifth of known 
 plants, are sub-divided into 
 
 Class I. Dictyogenae. Veins of the leaves in form of 
 a network ; wood of stem in perennials arranged 
 in a circle with a central pith. Examples The 
 yam, flowering rush, orchis, asparagus, palm, 
 ginger, banana. 
 
 Class II. Petaloidese. Leaves with parallel veins ; 
 flowers, a coloured floral envelope, or of Avhorled 
 scales. Examples Water plantain, lily family, 
 hyacinth, tulip. 
 
 Class III. Glumiferae. Flowers, glumaceous or scaly, 
 consisting of imbricated scales, called bracts* 
 Veins of the leaves parallel. Examples The 
 cotton sedge, and the grasses, including all the 
 corn tribe, and the bamboo. 
 
 Rhizogens. These form a connecting link between 
 the flowering and flowerless plants, and have been 
 placed differently by various botanists. 
 
 They have an embryo without seed-leaves, the fruit 
 springing from a thallus. The stem is a mass of
 
 BOTANY. 47 
 
 cellular tissue without fibre, and is furnished with 
 cellular scales in place of leaves. 
 
 They are few in number, parasitical in growth, and, 
 as in the case of the Rafflesia, appear to be a mere 
 flower growing on the branch of a tree, having large 
 fleshy lobes like the fungi. They have all a bitter 
 flavour and strong smell, and are found only in tropical 
 climates. 
 
 QUESTIONS ON CHAPTER XII. 
 
 Who first attempted to classify plants ? 
 
 Name other botanists who succeeded him. 
 
 What system was long iu use ? 
 
 How did Linnaeus arrange plants ? 
 
 Who invented the Natural System ? 
 
 Where does Candolle begin his classification ? 
 
 What are the two great divisions ? 
 
 How are the Phsenogams sub-divided ? 
 
 Name the four classes of Exogenous plants. 
 
 What proportion of the vegetable kingdom are Endogens ? 
 
 Give some examples of Dictyogense. 
 
 What is peculiar of the Petaloideae ? Examples ? 
 
 What is meant by glumaceous ? 
 
 What are Khizogens ? What is the chief example ? 
 
 CHAPTEE XIII. 
 
 Division II. Cryptogamia, or flowerless plants. 
 These are sub-divided into Acwgens and Thallogens. 
 
 Acrogens have the embryo without seed-leaves, and 
 plants with a distinct stem bearing leaves or branches. 
 They have no primary root, and only grow in one 
 direction upwards. 
 
 This includes the fern tribe, the floating pepper- 
 wort, the lycopodium, or club-moss, and other mosses, 
 and the hepaticse or liverworts.
 
 48 OUTLINES OF SCIENCE. 
 
 Thallogens represent the lowest form of vegetable 
 life, sometimes consisting of a single cell, and in their 
 highest development are only a collection of cells. 
 
 This sub-division includes the lichens, fungi, or 
 mushroom, and toadstool tribe, the charas, a water- 
 jplant, and the seaweeds. 
 
 Cryptogamia, or flowerless plants. These are 
 ferns, mosses, lichens, fungi, and algse, or seaweed, 
 and are called flowerless because they have neither 
 stamen nor pistil, nor any seed proper; but in the 
 case of ferns are produced from or propagated by very 
 small bodies called sporules, which in ferns are found 
 under the frond or leaf. They are believed to be 
 composed of cellular tissue without spiral vessels, but 
 their composition is less understood than that of the 
 flowering plants. 
 
 Mosses, which seem to be among the lowest of the 
 kind, are found in damp places, on rocks, trees, walls, 
 &c., chiefly in cold or temperate climates. The moss 
 is reproduced from sporules which are found at the 
 end of a stalk, in an urn or theca, which is closed 
 with a lid called an operculum. There are 800 diffe- 
 rent species of mosses. 
 
 Lichens are stemless and leafless, consisting of a 
 tough wrinkled substance called a thallus, and of 
 various colours. These are reproduced from sporules, 
 which are formed within the cellular tissue of which 
 the plant is composed. This, like moss, grows in 
 cold and damp climates, and there are said to be 
 more than 2000 different species. 
 
 Fungi, such as the mushroom, toadstool, &c., are of 
 various form and quality, some being excellent food, 
 and others poisonous. Of rapid growth, they as 
 quickly perish. 
 
 are water-plants growing either in fresh or
 
 BOTANY. 
 
 49 
 
 salt water. Of these seaweed affords numerous and 
 curious examples, and this tribe approach nearest to 
 the lowest grades of the animal kingdom, so that in 
 some examples of both it is difficult to decide which 
 is the animal and which the vegetable. Much sea- 
 weed was formerly burned for its ashes, called kelp, 
 and is still used as manure. 
 
 QUESTIONS ON CHAPTEE XIII. 
 
 What is the meaning of Cryptogamia ? 
 
 What example is given of the Acrogens ? 
 
 What represents the lowest order of plant life ? 
 
 Name the various Thallogens. 
 
 The chief examples of Cryptogamous plants. 
 
 How are the Cryptogams propagated ? 
 
 Describe especially the seed of the moss. 
 
 What is a lichen ? How many mosses are known ? 
 
 Where are these plants usually found ? 
 
 What are the chief examples of Fungus ? 
 
 What is said of their growth ? 
 
 What are Algse ? What is said of this trihe? 
 
 What use is or has been mad'e of seaweed ? 
 
 How many varieties of lichen are known ? 
 
 CHAPTER XIV. 
 
 THALAMIFLOR-E AND CALYCIFLOR.E. 
 
 Class Thalamiflorae. This sub-class includes those 
 exogenous plants which 
 have both calyx and 
 corolla, and have the 
 sepals of the calyx, the 
 petals of the corolla, 
 and the stamens or 
 seed-vessels, all grow- 
 ing separately and dis- 
 tinct from each other. 
 
 As in other classes, F 'g 14 -
 
 50 OUTLINES OF SCIENCE. 
 
 there is a great diversity in the size of the members 
 of this. 
 
 The best known examples are the common butter- 
 cup, poppy, water-lily, wallflower, violet, flax, lime- 
 tree, and orange. 
 
 These are commonly arranged in eight groups 
 called orders, and are named as follows : 
 
 Order 1. Rammciilaceae, including aconite, ane- 
 mone, buttercup, clematis, Christmas rose, marigold, 
 peony, larkspur, and columbine. These usually grow 
 in damp places, and are all poisonous. 
 
 Order 2. Papaveraceae, including all the poppy 
 tribes. These are all possessed of narcotic or sleep- 
 giving properties. 
 
 Order 3. Nymphaceae, containing the water-lilies 
 and lotus, all being water-plants. 
 
 Order 4. Cruciferae. This order is in the vegetable 
 kingdom what the order Ruminantia is in the animal. 
 It includes the cabbage, turnip, cress of all kinds, 
 mustard, and others which are found in all climates, 
 and are all health-giving, and therefore valuable to 
 man. It may be known everywhere by its four sepals 
 and petals in form of a cross. 
 
 Order 5. Violacese, including all the violet tribe. 
 
 Order 6. Linacese, of which the flax is the common 
 example. 
 
 Order 7. Tiliaceae, containing the lime-tree. 
 
 Order 8. Aurantiaceae, containing the orange, 
 and lemon, shaddock, grape fruit, and others, all 
 natives of hot climates.
 
 BOTANY. 51 
 
 Class Calyciflorse. This sub-class contains those 
 plants which agree in 
 having four or five sepals 
 and petals, and numerous 
 stamens, more or less fixed 
 to the calyx. 
 
 The type of the order is 
 the dog-rose, or common 
 wild rose. 
 
 It is very extensive and Fig. is. 
 
 important to man and other animals, as it contains 
 valuable fruits and vegetables, as well as beautiful 
 flowers. It is usually divided into eight orders. 
 
 Order 1. Leguminosae, which includes all those 
 plants such as the pea, bean, gorse, and others, which 
 have papilionaceous flowers, or flowers like the wings 
 oipapilio, a butterfly, adhering to the calyx. 
 
 Besides the common vegetables mentioned, it con- 
 tains also the acacia, laburnum, ebony, and tamarind 
 trees. 
 
 Order 2. Rosaceae, containing all the roses, the 
 apple, pear, strawberry, and cinque-foil, and all the 
 amygdalous or almond-like plants such as the almond, 
 cherry, plum, apricot, peach, laurel, &c. 
 
 All the latter contain an active poison in their 
 kernels or seeds, called Ferrocyanic, or Prussic acid. 
 
 Order 3. Cucurbitaceae, including the cucumber, 
 (from cucurlita, a gourd,) melon, and the various 
 gourds and vegetable marrows. 
 
 Order 4. Grossulareae, including all the goose- 
 berry, currant, &c. These have usually green flowers, 
 and frequently prickly stems. 
 
 Order 5. Umbelliferae, containing all the carrot 
 and parsnip tribe, the hemlock, fennel, and parsley. 
 This order is known by the growth of the floAvers in 
 umbels or bunches. 
 
 52
 
 62 OUTLINES OF SCIENCE. 
 
 Order 6. Loranthese, including the misletoe and 
 some other parasitic plants, usually without a corolla. 
 
 Order 7. Crassulacese, containing the houseleek, 
 stone-crop, and others, all of which have succulent, or 
 fleshy leaves. 
 
 Order 8. Compositae. The plants of this order have 
 small flowers collected together into dense bunches or 
 heads, surrounded by a case called an involucre. 
 
 The simplest example of this order is the dande- 
 lion ; it also contains the sunflower, artichoke, 
 groundsel, daisy, lettuce, endive, coltsfoot, chamomile, 
 and others. 
 
 QUESTIONS ON CHAPTER XIV. 
 
 What plants are included in Thalamiflorse ? 
 
 What is said about the size of the plants ? 
 
 Into how many orders is this class arranged ? 
 
 What is the best example of Ranunculacese ? 
 
 Where do they grow, and what is their peculiarity ? 
 
 What order contains the poppy plants ? 
 
 For what are the poppy plants remarkable ? 
 
 What are included in the NyinphacesD ? 
 
 Which is the most important order of the class? 
 
 What animal order does it resemble ? 
 
 Give examples of the order Cruciferse. 
 
 How may this order be easily known ? 
 
 What plants belong to the fifth order ? 
 
 To which order does the flax plant belong ? 
 
 What is included in the Tiliacese? 
 
 What fruits are contained in Aurantiacese ? 
 
 Where are the Aurantise found ? 
 
 What is the type of class Calyciflorse ? 
 
 Why is this class very important to man ? 
 
 How is this class divided ? Name them in order. 
 
 What are included in the Leguniinosse ? 
 
 What are the chief examples of Eosacese ? 
 
 What is peculiar to the kernels of amygdalous plants ? 
 
 To what order does the cucumber belong ? 
 
 What is notable in the flowers of Grossularece ? 
 
 Why are the umbelliferous plants so called ?
 
 BOTANY. 
 
 53 
 
 What plants belong to this order ? 
 
 What order includes the misletoe ? 
 
 What is peculiar to the Crassulacese ? 
 
 Name the chief flowers of the order Composite. 
 
 What is peculiar to the flowers of this order ? 
 
 CHAPTER XV. 
 COROLLIFLOS.E. 
 
 Class Corolliflorae. This sub-class contains eight 
 orders which may be known by 
 the corolla or flower-cup being 
 monopetalous, that is, instead of 
 being divided like the dog-rose, 
 or daisy, the corolla is in one 
 piece, as the primrose. 
 
 Order 1. Boragineae, includ- 
 ing the forget-me-not, hound's 
 tongue, and the borages. 
 
 Order 2. Primulacese, includ- 
 ing the common primrose, cow- Fig. is. 
 slip, oxlip, pimpernel, moneywort, &c. 
 
 Order 3. Convolvulaceae, found twining in gardens 
 and hedges, contains the various kinds of convolvulus 
 and bindweed. 
 
 Order 4. Oleaceae, the olive, lilac, ash, and common 
 privet. 
 
 Order 5. Gentinese, the gentian, yellow-wort, cen- 
 taury, and buckbean, all valuable in medicine. 
 
 Order 6. Solonaceae, or nightshades, includes several 
 poisonous plants, such, as the deadly nightshade, man- 
 drake, stramonium, or thorn-apple, henbane, and 
 tobacco. It also includes the potato and the egg- 
 plant. 
 
 53
 
 64 OUTLINES OF SCIENCE. 
 
 Order 7. Labiatee. This order contains the frag- 
 rant lavender, and the useful herbs sage, peppermint, 
 thyme, horehound, the dead nettle, rosemary, and 
 ground ivy. 
 
 Order 8. Scrophulariacese, including the digitalis or 
 foxglove, the snapdragon, toad- flax, speedwell, broom- 
 rape, and euphrasia or eye-bright. The digitalis and 
 euphrasia are valuable medicines. 
 
 EXOGENS. 
 
 Class Monochlamydeae. The plants of this sub- 
 class are distinguished by having only a single floral 
 envelope, the flower being in one piece. It includes 
 most of our timber and other large trees. 
 
 It is also divided into eight orders. 
 
 Order 1. Polygonaceae, containing buckwheat, 
 dock, sorrel, and knotgrass. 
 
 Order 2. Urticaceae (from urtica, a nettle). This 
 
 order includes the common nettle, the hop, hemp, 
 
 mulberry, and fig, the first three of which have very 
 strong fibres. 
 
 Order 3. Corylaceae, including the oak, beech, chest- 
 nut, hazel, and hornbeam. 
 
 Order 4. Salicaceae (from salix, a willow,) contains 
 all the willows, the sallow and osier, and the poplar 
 and aspen trees. 
 
 Order 5. Betnlaceae (from belula, a birch,) contains 
 the alder and birch trees. The alder makes the finest 
 charcoal, and the bark of the birch is used in 
 tanning. 
 
 Order 6. Ulmaceae, the elm-tree tribe, very durable 
 timber. 
 
 Order 7. Pinaceae, or conifers, including the var- 
 ious pine and fir trees, and also the yew, cypress, and
 
 BOTANY. 55 
 
 juniper. Tne leaves are all narrow and hard, and the 
 wood is resinous. 
 
 Order 8. Lauraceae, all aromatic plants, such as 
 the camphor, laurel, bay, cinnamon, and sassafras. 
 
 QUESTIONS ON CHAPTER XV. 
 
 How are the CorolliflorEC easily known ? 
 
 Name the eight orders of this class. 
 
 What is meant by the word Monopetalous ? 
 
 To which order does the forget-me-not belong ? 
 
 What plants belong to the Primulse and Gentineffi ? 
 
 In what are the Gentinese valuable ? 
 
 Where are the Convolvulacese found ? 
 
 Give examples of the order Oleacese. 
 
 To what order do the potato and tobacco belong ? 
 
 What is peculiar to many of this order ? 
 
 To which order do lavender and sage belong ? 
 
 Name some valuable plants in ScrophulariaceEB. 
 
 How is the class Monochlamydese known ? 
 
 Name its eight orders in succession. 
 
 What examples are given of Polygon acese ? 
 
 Which order contains many fibrous plants ? 
 
 Which order contains many aromatic plants ? 
 
 What is peculiar to the leaves and wood of Coniferse ? 
 
 What order supplies the best charcoal ? 
 
 CHAPTER XVI. 
 
 ENDOGEN3I AND ACROGENJE. 
 Class Endogenae. This class includes seven orders, 
 all of which have the roots grow- 
 ing from within the radicle of the 
 seed, no central pith, and no outer 
 bark. They have leaves with veins 
 parallel to the mid-rib, or centre Fig. 17. 
 
 rib, (See Fig. 17,) sepals, petals, and stamens, in 
 groups of three, six, nine, or twelve, and the seeds 
 have only one seed-leaf.
 
 
 56 OUTLINES OF SCIENCE. 
 
 Order 1. Palmacese, includes the cocoa-nut, flax, 
 date, and other palm trees, all of which have leaves 
 and flowers only at the top. '.The fruit is generally a 
 nut, as the date or cocoa-nut. 
 
 Order 2. Liliacese. This order consists chiefly of 
 bulbous plants, as the various lilies, the tulip, onion, 
 garlic, and asparagus. ^ 
 
 Order 3. OrcMdaceae, containing the varieties of 
 orchis, many of which have a great similarity in their 
 flowers to insects, birds, or flies as the bee-orchis, 
 fly-orchis, and others of a similar kind. 
 
 Order 4. Iridaceae, including the crocus, and var- 
 ious flags. 
 
 Order 5. Juncacese, the soft rush, a common rush. 
 
 Order 6. Cyperacese, including the bull-rush and 
 sedge. 
 
 Order 7. Graminaeese (from gramen, grass,) con- 
 tains all the grasses and varieties of grass-seed so 
 important both to man and animals. The chief ex- 
 amples are the common wheat, oats, barley, rye, rice, 
 reeds, meadow, and other grasses. 
 
 Class Acrogenae. Plants of this class have neither 
 fruit nor flower, but commonly the spores or seed- 
 vessels are arranged on the leaves. The root grows 
 from any part of the seed, the thick parts are in a 
 zigzag form ; the leaves have either no veins, or 
 simply forked veins. 
 
 This class is divided into seven orders. 
 
 Order 1. Filicese. This includes all the various 
 ferns. 
 
 Order 2. Lycopodiaceae, including the Lycopodium 
 and club mosse*.
 
 BOTANY. 57 
 
 Order 3. Equisetacese, the horsetail which grows in 
 marshes. 
 
 Order 4. Musci, the hair-moss, and those which 
 grow on damp wood or stone. 
 
 Order 5. Fungi, the various mushrooms, toadstools, 
 pu^F-balls, mildew, and smut. Many of the Fungi 
 besides the mushroom are said to be good for food, 
 but great care is required in the use of them. 
 
 Order 6. Lichenese, including the yellow cup and 
 other lichens. 
 
 Order 7. Algse, the various kinds of sea-weed, of 
 which there are an enormous number, nearly all 
 adapted to grow under water. Some are used as 
 articles of food, and all form good manure. 
 
 QUESTIONS ON CHAPTER XVI. 
 
 Name the peculiarities of the Endogens. 
 
 Name the orders of the class Endogence. 
 
 Bow do you distinguish an endogen leaf from an eiogenP 
 
 In what order are the sepals, &c., usually placed ? 
 
 What are the chief examples of the Palmacece ? 
 
 "What is peculiar to the growth of that order ? 
 
 Which contains bulbous plants ? Of what kind? 
 
 What is remarkable about the Orchidacese ? 
 
 Give examples of orders four, five, and six. 
 
 Which is the most important of these orders ? 
 
 What is peculiar to the class Acrogens ? 
 
 Name its seven orders in succession. 
 
 Name the examples of the order Filiceee ? 
 
 Where do the Eo^uisetacese grow ? And the Musci?
 
 58 OUTLINES OF SCIENCE. 
 
 CHEMISTRY. 
 
 INORGANIC AND ORGANIC. 
 
 CHAPTER XVII. 
 
 CHEMISTRY teaches us the nature of those elements 
 that compose all the substances with which we are 
 acquainted, the mode of their combinations, and the 
 properties of the compounds which result from them. 
 
 This science is comparatively modern, but its 
 results and discoveries have been as useful as they are 
 wonderful. Every art and every branch of commerce 
 has been indebted to it for development and improve- 
 ment. 
 
 Alchemy. The students of this science, previous 
 to the seventeenth century, were chiefly those 
 alchemists, as they were called, who had an opinion 
 that the baser metals could be changed into gold by 
 the aid of something which they called the " philo- 
 sopher's stone." Many persons followed this pursuit 
 in the middle ages, wasting their substance and their 
 lives to no purpose, so far as gold was concerned, but 
 their labours resulted in the discovery of many useful 
 substances, and paved the way for a more intelligent 
 study of the subject under present notice. 
 
 Chemistry is divided into Inorganic and Organic. 
 The former treats of the simple bodies, or elementary 
 substances, namely, those which cannot be further 
 analysed or separated, while organic treats of their
 
 CHEMISTRY. 
 
 69 
 
 various compounds, chiefly in the animal and vege- 
 table kingdom. 
 
 Elements, or Simple Substances. These, in ancient 
 times, were said to be earth, air, fire, and water. The 
 discovery of elements has greatly increased during the 
 present century, and the chemist has shown that the 
 original elements, as they were called, are all com- 
 pounds, or, as in the case of fire, the product of com- 
 bustion. Thus air is composed of oxygen, nitrogen, 
 and a little carbonic acid ; water, of oxygen and 
 hydrogen ; and earth of various substances, which 
 may be analysed or loosed from one another, and 
 shown to be elements. 
 
 Table of Elements. The number of these at pre- 
 sent is sixty-five ; twenty years ago only fifty-four 
 were enumerated as chemists proceed in their re- 
 searches, they will probably discover more. So long 
 as a substance cannot be separated into any com- 
 ponent parts, it is called an element, as gold, silver, 
 and other metals. The following is the list of known 
 elements, which are so called because they cannot be 
 separated or further reduced : 
 
 Aluminium 
 
 Chlorine 
 
 Lanthanum 
 
 Norium 
 
 4ntimony 
 
 Chromium 
 
 Lead (Plum- 
 
 Osmium 
 
 Arsenic 
 
 Cobalt 
 
 bum) 
 
 Oxygen 
 
 Barium 
 
 Copper 
 
 Lithium 
 
 Palladium 
 
 Beryllum 
 
 Didymium 
 
 Magnesium 
 
 Phosphorus 
 
 Bismuth 
 
 Erbium 
 
 Manganese 
 
 Platinum 
 
 Boron 
 
 Fluorine 
 
 Mercury (Hy- 
 
 Potassium 
 
 Bromine 
 
 Gold (Aurum) 
 
 drargyrum) 
 
 Rhodium 
 
 Cadmium 
 
 Hydrogen 
 
 Molybdenum 
 
 Rubidium 
 
 Caesium 
 
 Indium 
 
 Nickel 
 
 Ruthenium 
 
 Calcium 
 
 Iodine 
 
 Niobium 
 
 Selenium 
 
 Carbon 
 
 Iridium 
 
 Nitrogen, or 
 
 Silicon, or 
 
 Cerium 
 
 Iron (Ferrum) 
 
 Azote 
 
 Silicium
 
 OUTLINES OF SCIENCE. 
 
 Silver, or 
 Argentum 
 Sodium, or 
 Natrium 
 Strontium 
 
 Sulphur 
 Tantalum 
 Tellurium 
 Terbium 
 Thallium 
 
 Thorium 
 Tin, or 
 Stannum 
 Titanium 
 Tungsten 
 
 Uranium 
 Vanadium 
 Yttrium 
 Zinc 
 Zirconium 
 
 Of the above, fifty-two are metallic elements, and 
 thirteen non-metallic. Of the non-metallic, hydrogen, 
 nitrogen, and oxygen are gases ; chlorine and fluorine 
 are vapours ; bromine is a fluid ; boron, carbon, iodine, 
 phosphorus, selenium, and sulphur are solids. Those 
 of them which form salts in combination with other 
 substances, are called halogens. 
 
 Affinity, or Chemical Attraction. Chemical affinity 
 differs from the attraction of cohesion, and of gravita- 
 tion, because it changes the nature of the substances 
 upon which it acts. The results of affinity are as 
 important as they are surprising. For example two 
 gases will form a solid. If a jar be held over hydro- 
 chloric acid, and another be held over a solution of 
 ammonia, and the two jars be placed mouth to mouth, 
 the two gases will combine and form the solid sal- 
 ammoniac, which is seen in the form of a white smoke, 
 and crystals are deposited. 
 
 Two fluids will form a solid. Add sulphuric acid to 
 a solution of chloride of calcium, and a solid sulphate 
 of lime will be formed. 
 
 Spontaneous Combustion is formed by throwing 
 turpentine upon a mixture of nitric acid and strong 
 sulphuric acid. 
 
 Also, if a few drops of sulphuric acid be dropped 
 on a mixture of powdered loaf sugar and chlorate of 
 potash, it will take fire spontaneously. 
 
 Combustion under warm water is caused by passing 
 a stream of oxygen through a tube upon a piece of 
 phosphorus.
 
 CHEMISTRY. 61 
 
 Affinity changes colour, and is useful in testing 
 various substances. If a solution of iodide of potas- 
 sium be mixed with another of sugar of lead, both 
 colourless, the result will be a yellow powder. 
 
 If iodide of potassium be mixed with a solution of 
 corrosive sublimate (a preparation of mercury), a 
 beautiful red powder is formed. 
 
 If a few drops of tincture of galls be dropped into 
 a solution of sulphate of iron, a deep black colour will 
 result, which is the base of the common black ink. 
 Many similar interesting examples of change might 
 be mentioned. 
 
 QTTESTIOtfS ON CHAPTER XVII. 
 
 What does Chemistry teach ? 
 
 "What were the old chemists called ? 
 
 How were the old alchemists employed ? 
 
 Of what does Organic Chemistry treat ? 
 
 What was the old notion ahout simple elements ? 
 
 What are the component parts of air and water ? 
 
 What is the number of the simple elements ? 
 
 Why are they so called ? Have they increased lately ? 
 
 How many of them are metals? and non- metallic? 
 
 What is a halogen ? What is affinity ? How does it affect 
 
 substances ? 
 
 Give some examples from two gases ; from two fluida. 
 What is said of spontaneous combustion ? 
 How can we secure combustion under water ? 
 How is affinity especially useful ? 
 What colours result from compounds of iodine? 
 How is a deep black colour obtained ? 
 
 CHAPTER XVIII. 
 
 Definite Proportion, or Combination. When we 
 speak of chemical compounds, we refer to the fact 
 that the ingredients which form them are always 
 united in them, in the same proportion as to weight. 
 
 6
 
 62 OUTLINES OF SCIENCE. 
 
 In water, which is a compound of oxygen and 
 hydrogen, the weight of the oxygen is always eight 
 times that of the latter, and the same may be said 
 of other compounds. Common salt contains 35 
 parts of chlorine to 23 of sodium, Glauber's salt 
 always 80 of sulphuric acid to 62 of soda, and so on. 
 
 Various Compounds. It is also remarkable that 
 the same elements combined in different proportions 
 produce a different result. This is especially noticeable 
 in the compounds of oxygen and nitrogen. The sim- 
 plest of these combinations is that of nitrous oxide, or 
 laughing gas, consisting of 28 parts of nitrogen, and 
 16 of oxygen ; the next nitn'c oxide containing the 
 same portion of nitrogen with twice the quantity (32) 
 of oxygen ; then follow nitrows acid, conbining 28 
 nitrogen and 48 oxygen; hyponi^n'e acid, which 
 equals 28 nitrogen and 64 oxygen, and lastly, the 
 very corrosive and powerful nitnc acid, which consists 
 of 28 nitrogen and 80 oxygen. 
 
 Here it will be seen that the portion of nitrogen is 
 always 28, while the proportions of oxygen increase 
 from 16 to 32, to 64, to 80, or to twice, thrice, four, 
 and five times the portion in nitrous oxide. The 
 same law applies to other compounds, and there is no 
 intermediate proportion. Should the element in a 
 compound be more than 16, it is sure to be 32 or 
 more, and if more, 48 or more, &c. 
 
 Laws of Combination. The knowledge of these 
 definite proportions is of the utmost value to those 
 who have to manufacture chemical compounds. 
 
 They know that the same compound, whether 
 obtained in Europe or America, consists invariably of 
 the same ingredients, and that those elements are 
 always contained in the same proportion by weight. 
 
 Chemical Symbols. Every compound is repre- 
 sented by its equivalent symbols, and the proportions
 
 CHEMISTRY. 63 
 
 of each element contained in it. Thus water, which 
 is always composed of two atoms of hydrogen and one 
 of oxygen, is represented by the formula HoO. 
 
 When a candle is burned, there is a consumption of 
 two elements, carbon and hydrogen. The carbon 
 burning in the air unites with two parts of oxygen, 
 and forms carbonic acid, Avhich is noted down as C ; , 
 while two parts of the hydrogen unite with one of the 
 oxygen and form water, H 2 0. The products of this 
 combustion, therefore, are carbonic acid and water, 
 and in a similar manner every known chemical com- 
 pound is symbolised. 
 
 Chemical Language. Many of the names of 
 chemicals are derived from the alchemists, such as 
 spirit of wine, spirit of salt, &c., and many of the 
 older elements have two names, as sulphuric acid, and 
 its common term, oil of vitriol, sulphate of copper, 
 bluestone, &c. 
 
 Compounds are termed primary when they consist 
 of only two elements, as water of oxygen and 
 hydrogen (H 0), sulphuric acid of sulphur and oxygen 
 (S 3 ), common salt, chlorine and sodium (NaCh), 
 vermilion of mercury and sulphur (Hg 3 S), &c. 
 
 Secondary, when formed of two primary, as sul- 
 phate of soda, which is composed of sulphuric acid 
 and soda (S 3 + Na 0). 
 
 Ternary compounds are those which contain two 
 secondary substances, or three elements, as common 
 dry alum, which contains sulphate of soda, potash, 
 oxygen, and aluminium. 
 
 Binary Compounds. The chief of these are those 
 of the non-metallic elements, such as oxygen, sulphur, 
 and chlorine, with each other, or with the metals. 
 
 Compounds of oxygen are called oxides. Common 
 rust is an oxide of iron ; red lead, an oxide of lead. 
 
 62
 
 64 OUTLINES OF SCIENCE. 
 
 Chlorides. Compounds of chlorine are called 
 chlorides, as common salt, the chloride of sodium, 
 calomel, the chloride of mercury, &c. 
 
 Compounds of sulphur are called sulphurets or sul- 
 phides ; vermilion is the sulphide of mercury, and 
 galena the sulphide of lead. 
 
 Protoxides, &c. The same elements as we have 
 seen in the union of nitrogen and oxygen, form com- 
 binations of various proportions. The first is called 
 a protoxide, from protos, first, as nitrous oxide. The 
 next combination is called a deutoxide, as nitric oxide, 
 and so on with the tritoxide, up to the hyper or 
 peroxide, which is the highest combination of oxygen 
 with any other element. 
 
 Bases. In these combinations spoken of as oxides, 
 the element which combines Avith the oxygen is called 
 the base ; thus, lead is the base of the oxide of lead, 
 iron, the base of oxide of iron, and so on. 
 
 Acids. Oxides which contain a large proportion of 
 oxygen, will redden vegetable blues, and have an acid 
 taste. They are therefore called acids, as sulphuric 
 acid, nitric acid, and others. 
 
 Salts. These are combinations of acids with oxides. 
 Thus sulphuric acid combining with potash, forms the 
 salt called sulphate of potash ; Avhen it combines with 
 soda, sulphate of soda, or Glauber's salt ; and when 
 it combines with magnesia, it forms Epsom salt, or 
 sulphate of magnesia. If these salts contain an acid 
 ending in ic, as sulphuric, they are called sulphates, 
 but if the acid contained ends in ous, they are called 
 sulphites. 
 
 The same rule applies to the other acid combina- 
 tions, as nitrates, chlorates, hydrates, phosphates, &c.
 
 CHEMISTRY. G5 
 
 QUESTIONS ON CHAPTER XVIII. 
 
 Give some examples of definite proportion. 
 Name some remarkable compounds of oxygen. 
 What are the proportions of nitrous and nitric acids P 
 Why is a knowledge of this subject important ? 
 What are the chemical symbols for water? 
 What results from the burning of a candle ? 
 What is a primary compound ? a secondary ? 
 What elements are found in common alum ? 
 What are the compounds of oxygen called ? 
 What is oxide of lead ? What is a chloride ? 
 What is a protoxide ? What is a peroxide ? 
 What is meant by the base of an oxide ? 
 When much oxygen is contained, what is it called ? 
 What is a salt ? How is sulphate of potash formed ? 
 Distinguish, between sulphates and sulphites ? 
 
 CHAPTEE XIX. 
 
 THE OASES OXYGEN, HYDROGEN, AND NITEOGEN. 
 
 Oxygen. Of these, the most abundant, and per- 
 haps important, is oxygen, as it is more widely 
 diffused than any other. It forms one-fifth of the 
 volume of air, and eight-ninths of water by weight, 
 besides entering largely into the composition of all 
 the materials of the globe ; neither animals nor vege- 
 tables can live without it. 
 
 Oxygen is colourless, and heavier than common air, 
 is easily procured by heating chlorate of potash in a 
 retort, and is used for many brilliant experiments. 
 It will support combustion, but will not burn, so that if 
 a piece of lighted charcoal or red-hot wire, or a small 
 piece of phosphorus, be placed in a jar of it, those 
 articles burn very brilliantly until the oxygen is 
 exhausted, without fear of explosion. Its chief com- 
 pounds, which are very abundant, are the oxides of 
 the various metals. 
 
 63
 
 66 OUTLINES OF SCIENCE. 
 
 Hydrogen. This gas is colourless, and without 
 taste or smell, and it forms one-ninth part by weight 
 of all water. It is the lightest known gas, being 
 fourteen times lighter than air, and sixteen times 
 lighter than oxygen. It burns, but will not support 
 combustion, so that by putting a light to the mouth 
 of a jar of it, it is exploded at once with a pale yellow 
 flame. 
 
 Lightness. On account of its lightness, it is used 
 for filling balloons, but as it does not exist in a sepa- 
 rate form, it has to be prepared. The simplest mode 
 of obtaining it, is to send a galvanic current through 
 water, which separates the hydrogen from the 
 oxygen. 
 
 The usual mode of preparation, is to pour a mix- 
 ture of sulphuric acid and water on small pieces of 
 zinc or iron filings, Avhen the water is decomposed, 
 and hydrogen immediately set free. If the mixture 
 be placed in a bottle, and a tube be thrust through 
 the cork, the gas may be burnt at the end of the tube. 
 This is called the philosophic candle. Care must be 
 taken to allow all the common air to escape before the 
 light is applied, because a mixture of oxygen and 
 hydrogen is very explosive, and both the cork and 
 tube would probably be blown out of the bottle. 
 
 The Drummond Light. This powerful light is 
 formed by burning a double stream of oxygen and 
 hydrogen on a piece of lime, whence it is called the 
 oxyhydrogen or lime light. It may be seen to a dis- 
 tance of sixty miles, and is especially useful in light- 
 houses. 
 
 Nitrogen, or Azote. This gas constitutes about 
 four-fifths of the atmosphere, and is Avithout colour, 
 taste, or smell. It does not burn, nor will it support 
 combustion, and when separated from oxygen will not 
 support life. It is found in abundance in nitre, salt-
 
 CHEMISTRY. 67 
 
 petre, and other nitrates, and in coal, and is a con- 
 stant ingredient in plants and animals. 
 
 Compounds. Several of the compounds of nitrogen 
 are of great importance, the chief of which are nitric 
 acid, which, as we have seen, is a compound of oxygen 
 28, and nitrogen 80, and which is so powerful that it 
 dissolves many of the metals, and all animal matter. 
 If a small piece of copper wire be placed in nitric 
 acid, it begins instantly to dissolve, and the acid 
 turns green, while reddish fumes escape. Nitrogen 
 and hydrogen form the strong pungent compound 
 ammonia, from which hartshorn is made. It is also 
 a very important ingredient in food. 
 
 Chlorine and Fluorine are Gaseous Vapours. 
 Chlorine, which is of a yellowish green colour, 
 abounds in nature. It is a chief part of common 
 salt, which is chloride of sodium, as well as of rock 
 salt, some earths and some mineral waters. It is 
 easily obtained by heating a mixture of manganese 
 and hydrochloric acid, in a retort, and may be detected 
 by its pungent suffocating smell. As it destroys all 
 vegetable colours, it is very important as a bleaching 
 agent. 
 
 Chlorine has a strong affinity for metals, and pow- 
 dered antimony, if shaken in a jar of chlorine, will 
 burn brilliantly and form a chloride of antimony. A 
 similar result follows the introduction of copper or 
 gold-leaf. It does not unite with carbon, so that a 
 lighted candle burns very badly in it, and the carbon 
 falls to the bottom of the jar. If a paper soaked in 
 turpentine (a compound of carbon and hydrogen) be 
 introduced, it takes fire instantly, a- 1 ' chlorine has a 
 great affinity for hydrogen. The hydrogen unites 
 with the chlorine, and the carbon i? deposited as soot 
 on the side of the jar. Besi/' being useful in
 
 68 OUTLINES OF SCIENCE. 
 
 bleaching, it is valuable as a destroyer of noxious 
 smells and gases. 
 
 Fluorine is much less common than chlorine, and 
 may be obtained from fluor spar, when crushed and 
 heated with hydrochloric acid. It has such a strong 
 affinity for potash, a component of glass, that it can- 
 not be put in a glass vessel, which it would dissolve 
 by uniting with the potash in the glass. 
 
 It is used for writing or etching on glass, by simply 
 drawing the pattern with the fluid. It will not 
 combine with oxygen. 
 
 Bromine is so called from its disagreeable smell ; it 
 is found in mineral waters, and in all salt deposits, 
 and is usually obtained from the bittern which is left 
 in salt water, when the salt has been taken from it by 
 evaporation. It is of a dark brown, colour, destruc- 
 tive to the eyes, if allowed to touch them, and is a 
 deadly poison. It is employed, to a small extent, in 
 medicine and the arts. 
 
 QUESTIONS ON CHAPTER XIX. 
 
 Which gas is thought to be most abundant ? 
 
 Of what does it form the chief proportions ? 
 
 How is it procured ? What are its properties ? 
 
 Show that it supports combustion, but does not bum. Its 
 
 chief compounds. 
 
 How is hydrogen obtained ? Name its properties. 
 Describe what is called the Drummond light ? 
 Of what gas is the air largely composed ? 
 Name its chief properties. How is it obtained ? 
 Name some of its chief compounds. 
 What are chlorine and fluorine ? 
 How is chlorine obtained ? What are its properties ? 
 What happens when turpentine is introduced ? 
 To what uses is chlorine applied ? 
 Whence is fluorine obtained ? How is it used ? 
 What is the result of its affinity for potash ? 
 What is the peculiarity of bromine ? 
 How is it obtained ? and how used ?
 
 CHEMISTRY. 69 
 
 CHAPTER XX. 
 
 NON-METALLIC SOLIDS. 
 
 Boron. This is a dark olive substance found 
 chiefly in volcanic districts in union with soda in the 
 form of borax. It is of much use in the manufacture 
 of glass and porcelain, in the manufacture of solder, 
 and in medicine. Most of the metallic oxides, when 
 heated with borax, form coloured glasses. 
 
 Carbon. This element abounds in nature, in the 
 diamond, in common coal, charcoal, blacklead, and 
 other forms. The diamond is carbon in its purest 
 form, but what is called blacklead is often pure 
 carbon, or a compound of carbon and iron, called 
 graphite. It never contains any lead. Lampblack 
 and ivory-black are other forms of almost pure carbon. 
 
 Carbon combines with numerous other elements ; 
 its principal compounds are carbonic acid, carbonic 
 oxide, and its various compounds with hydrogen. 
 
 Carbonic Acid, a compound of carbon and oxygen, 
 is found everywhere in nature, and was called by the 
 ancients spiritus lethalis, or deadly air, and afterwards 
 fixed air. It is a colourless gas, with a sharp taste 
 and pungent smell, and will neither burn nor support 
 combustion, and is therefore destructive to human 
 life. It is the choke-damp of miners, and often causes 
 death to persons who go into old wells, lime-kilns, 
 distillers' or brewers' vats. 
 
 Preparation. Carbonic acid is prepared easily from, 
 limestone, marble, chalk, and other carbonates of 
 lime, by pouring diluted sulphuric acid over the 
 broken pieces of chalk. It may be also made, in its 
 purest form, by burning charcoal in oxygen. As it 
 is heavier than common air, it sinks to the bottom of 
 the vessel in which it is contained, and may be poured
 
 70 OUTLINES OF SCIENCE. 
 
 like water from one vessel to another. A lighted 
 candle is instantly extinguished by it, and it is there- 
 fore the custom, before going into a well or other 
 place where its presence is suspected, to let down a 
 light first. If there is life for the light, there is life 
 for man, and it is safe. 
 
 Soda Water is a strong solution of carbonic acid 
 gas in water, the gas having been forced into the 
 water by a heavy pressure, hence the bubbles, caused 
 by the gas escaping when the cork is withdrawn. 
 
 As we have shown in physiology, carbonic acid is 
 given off from the lungs, and when we breathe into 
 a glass of clear lime-water it becomes clouded, as a 
 carbonate of lime is formed by the union of the 
 carbonic acid with the lime. 
 
 Carbonic Acid in water dissolves the carbonate of 
 lime in rocks, and forms stalactites and stalagmites in 
 limestone caverns. It is prevented from accumulat- 
 ing to a dangerous extent in the atmosphere, by the 
 absorbing action of the vegetable kingdom, which 
 feeds -on it to a large extent. By this means, also, 
 plants are supplied with it that grow in soils which 
 do not contain it, such as siliceous, or flinty soils. 
 
 Carbnretted Hydrogen. The compounds of carbon 
 with hydrogen are both interesting and useful. The 
 most common is coal-gas, which depends for its light- 
 ing power on compounds of carbon and hydrogen, 
 called heavy carburetted hydrogen, or olefiant gas, 
 which burns with a bright red flame, and light car- 
 buretted hydrogen. 
 
 Firedamp. Light carburetted hydrogen, is that 
 gas which is generated in stagnant pools and in 
 marshy places where vegetables are decomposed under 
 water, and in some coal-pits, and burns with a light 
 blue flame. It is called Will-o'-the-Wisp, and is very
 
 CHEMISTRY. 71 
 
 dangerous in coal mines, when mixed with common 
 air, as it will explode with great violence. It is 
 called firedamp by the miners. As the carburetted 
 hydrogens are colourless, invisible, and without smell, 
 the danger is not suspected until the miner comes in 
 contact with this enemy. 
 
 The Safety Lamp. To preserve them from its 
 evil influence, the safety lamp was invented by Sir 
 Humphrey Davy. 
 
 The principle of it depends on the fact that flame, 
 which is gas at a white heat, will not pass through 
 small tubes or openings, such as the meshes of wire 
 gauze. As the flame of the safety lamp is surrounded 
 by wire gauze, the presence of firedamp is detected 
 by its influence on the flame within, and the miner is 
 warned of danger. 
 
 QUESTIONS ON CHAPTER XX. 
 
 What is Boron ? How is it usually found ? 
 
 Mention its various uses. 
 
 What are the various forms of carbon ? 
 
 What is blacklead ? What is lampblack ? 
 
 What are the compounds of carbon ? 
 
 What are the properties of carbonic acid ? 
 
 How is it prepared ? What are its uses ? 
 
 What are stalactites and stalagmites? 
 
 What prevents the accumulation of carbonic acid ? 
 
 What is a good test for carbonic acid ? 
 
 What are the useful compounds of carbon ? 
 
 What are its dangerous compounds ? 
 
 What is heavy carburetted hydrogen ? 
 
 When does carburetted hydrogen become explosive ? 
 
 What is the principle of the safety lamp ? 
 
 How is it useful to the miner ? 
 
 Distinguish between firedamp and chokedamp.
 
 72 OUTLINES OF SCIENCE. 
 
 CHAPTER XXL 
 
 Iodine is found chiefly in sea-weeds, and in sea-air, 
 and is obtained by burning sea-weed in masses. It 
 is a bluish-black crystalline solid, which crumbles 
 readily when pressed. When heated it gives a beau- 
 tiful violet colour, and when placed in contact with a 
 piece of dry phosphorus, affords a good example of 
 spontaneous combustion, as the two burst into flame 
 and form the iodide of phosphorus. 
 
 A solution of iodine of potassium is detected in- 
 stantly ; if starch be added, it turns a deep blue ; if 
 nitrate of silver, a pale yellow ; if acetate of lead, 
 a bright yellow ; if corrosive sublimate, a fine scarlet ; 
 while perchloride of platinum turns it to the colour 
 of claret or port wine. 
 
 Phosphorus. This substance is found in abundance 
 in union with lime, magnesia, guano, and bones of all 
 kinds. The bone derives its strength from the phos- 
 phates of lime and magnesia, which compose its hard 
 material, and from which the phosphorus of medicine 
 is prepared. This element is a component of grain 
 of all kinds, and of peas and beans, and much of the 
 various phosphates is used by agriculturists to enrich 
 the land. Phosphorus is kept in water, as it melts 
 at a temperature of 115, and would disappear in the 
 form of vapour, if left uncovered. 
 
 Very much of this substance is used in making 
 lucifer matches, as the heat caused by gentle friction 
 will cause the compound to take fire. 
 
 Selenium is a rare substance much resembling sul- 
 phur, in connection with which it is occasionally 
 found, and at present of no use either in medicines 
 or the arts. 
 
 Sulphur is a common element found free in abun- 
 dance, in volcanic districts, and is extensively diffused
 
 CHEMISTRY. 73 
 
 in combination with other substances, and with tho 
 metals. The best is brought from Sicily. It is of a 
 lemon colour, and is highly inflammable, burning 
 with a blue flame and forming the pungent sulphurous 
 acid, the smell of which is so well-known, and so dis- 
 agreeable. This acid is useful for bleaching purposes, 
 and is used to bleach wool, silk, sponge, and straw plait. 
 
 Sulphuric Acid. Sulphur burned in oxygen pro- 
 duces the powerful fluid called sulphuric acid, which 
 is highly useful both in medicine and the arts under 
 the name of oil of vitriol, and which, when heated, 
 dissolves most of the metals. The sulphur burned 
 in oxygen produces sulphurous acid, but the use of a 
 small portion of nitre in the combustion, changes it 
 into sulphuric acid, or oil of vitriol ; the vapour 
 passes out of the chamber in which it is produced, 
 and which is lined with lead, through a passage into 
 another chamber, the floor of which is covered with 
 water, in which the acid is condensed and collected. 
 
 Sulphuric acid is used in numerous chemical manu- 
 factures, as well as by dyers, calico printers, and 
 bleachers. 
 
 Eefiners of metal, soap and candle makers, soda- 
 water manufacturers, and numerous other trades, are 
 greatly dependent on its effects. 
 
 Affinity for Water. Vessels containing this acid 
 must be kept covered up, as it has a powerful attrac- 
 tion for water, and will grow weaker by absorbing 
 aqueous vapours from the atmosphere. 
 
 Great care is required in mixing it with water, as 
 they rapidly combine and evolve great heat, and often 
 break the vessel in which they are mixed. Two parts 
 of acid suddenly mixed with one part of water, will 
 cause heat equal to boiling. 
 
 Experiments. Sugar turned to charcoal. If you 
 place some powdered loaf sugar in sulphuric acid, or 
 
 7
 
 74 OUTLINES OF SCIENCE. 
 
 make a strong syrup, and pour diluted acid into it, 
 the acid takes the water from the sugar, and leaves 
 nothing but black charcoal behind, showing clearly 
 that the chief components of loaf sugar are water and 
 charcoal. 
 
 To show its bleaching powers, burn a little under a 
 glass in which a rose is suspended. The sulphurous 
 acid will quickly destroy the colour of the flower. 
 
 QUESTIONS ON CHAPTER XXI. 
 
 Where is Iodine found ? What are its peculiarities ? 
 What example does it give of spontaneous combustion ? 
 What colour does it give with corrosive sublimate ? 
 Of what is phosphorus a component ? 
 What is said of its temperature ? How is it kept ? 
 What is selenium ? Where is the best sulphur found ? 
 Mention some of its properties ? Its chief compound ? 
 In what art is sulphur especially useful ? 
 What persons are dependent on sulphuric acid ? 
 For what has it a great affinity ? How is it kept ? 
 What follows the sudden mixture of vitriol and water? 
 What are the chief components of sugar ? 
 How is it proved ? Is sulphur a good conductor ? 
 Show how to test its power of bleaching. 
 
 CHAPTER XXII. 
 
 THE METALS. 
 
 Aluminium. This is a metal of a light grey colour, 
 which is obtained from alumina, or pure cla} r . Clay 
 is usually termed an earth, but it is really a rust or 
 an oxide of the metal aluminium, that is, an earth 
 which has been produced by burning that metal in 
 oxygen. It was discovered by Davy in 1808. As 
 carbon is the essence of the diamond, so is alumina 
 of the ruby and sapphire one also forms the basis of 
 coal and coke, the other of pipeclay and earthenware. 
 
 Antimony is a bluish-white brittle metal, found in
 
 CHEMISTRY. 75 
 
 combination witn sulphur, which passes away in 
 vapour at a white heat, and takes fire spontaneously 
 in chlorine. 
 
 Arsenic, the common poison, is a grayish-white 
 metal more than five times heavier than water, which 
 is found in combination with the ores of cobalt and 
 nickel, from which it is separated. It oxidates 
 rapidly on exposure to the air, forming a white 
 powder. It burns spontaneously with a blue flame in 
 chlorine. 
 
 As it has often been the cause of death by poison, 
 both by accident and otherwise, it is well to know 
 that the best antidotes for it are calcined magnesia, 
 or the hydrated oxide of iron. 
 
 Tests. Its presence may be detected in any liquid 
 by the addition of a little sulphuric acid, and placing 
 thereon a piece of zinc : if the liquid contains arsenic, 
 a gas will be evolved called arseniuretted hydrogen, 
 which, if set on fire, will deposit tiny globules of 
 metallic arsenic on the side of the tube, or on a piece 
 of glass held over the flame. 
 
 Barium is a greyish heavy metal which is obtained 
 from barytes. 
 
 Bismuth is a white metal, nearly ten times the 
 weight of water. Its chloride is used by artists as 
 Spanish white or pearl white. 
 
 Cadmium is a metal similar to tin, found rarely in 
 combination with the ores of zinc. 
 
 Calcium is the base of lime, or calx, which is only 
 an oxide of this metal, as alumina, or pure clay, is an 
 oxide of aluminum. It was discovered by Davy in 
 1808, and has a brilliant lustre like silver. When 
 heated it burns into lime. It is the base of marble, 
 limestone, chalk, alabaster, and all the other car- 
 bonates of lime, which abound in nature ; it is found
 
 76 OUTLINES OI SCIENCE. 
 
 in the teeth and bones of animals, and is of the 
 utmost importance to builders and cement makers. 
 
 Plaster of Paris. Calcium is also the chief com- 
 ponent of gypsum, or plaster of Paris, which has a 
 strong affinity for water, and forms with it a hard 
 cement. 
 
 The lime is procured by burning the chalk or car- 
 bonate of lime with coals in a lime-kiln, when the 
 heat drives off all the carbonic acid. The purest 
 lime is obtained from marble, which is carbonate of 
 lime, that has been exposed to great volcanic heat. 
 
 Cerium is obtained from cerite, which is a very 
 rare mineral, white and brittle ; it will dissolve in 
 hydrochloric acid, but not in sulphuric acid. 
 
 Chromium is a greyish-white metal, which is found 
 in combination with the ores of lead, copper, and 
 especially chrome iron ore. It forms with oxygen 
 the green oxide, and in various compounds is us,ed in 
 great quantities by dyers, artists, and bleachers. 
 
 Compounds. Chromic acid, with the salts of lead, 
 gives a yellow compound called chrome yellow ; with 
 black oxide of mercury, an orange ; from the bichro- 
 mate of potassium when heated, beautiful green 
 crystals are obtained. The red tint of the ruby is 
 said to be caused by the presence of chromic acid. 
 The chrornate of mercury is a red colour. 
 
 Cobalt is a metal of a reddish-grey colour, which 
 melts readily, and is much used in the colouring of 
 glass and porcelain. Chloride of cobalt is used as a 
 " sympathetic ink," which will turn blue when heated. 
 
 Copper. This well-known metal, which is called 
 brass in scripture, is found in all countries, and is the 
 only one of a red colour. It is of great use, on account 
 of the readiness with which it unites to form various 
 compounds, such as spelter, a hard solder formed vith
 
 CHEMISTRY. 77 
 
 equal parts of copper and zinc ; brass, which contains 
 1 6 parts of copper to 9 of zinc ; bell-metal, 3 parts 
 copper, and 1 of tin ; bronze, 9 parts copper to 1 of 
 tin. Copper is also used in making pinchbeck, 5 parts 
 copper and 1 zinc ; Manheim gold, 3 parts copper, 1 
 zinc, and a little tin. 
 
 In making sovereigns and other gold coin for cir- 
 culation, nearly one-twentieth copper is mixed with 
 the gold to harden it. 
 
 From its slight tendency to rust, copper is used to 
 cover or sheath the hulls of ships, and from its 
 pliability and strength it is extensively used as wire 
 in the vastly-increasing telegraph apparatus. 
 
 Solutions of Copper. In many places copper is 
 held in solution in streams of water, and as it has a 
 strong tendency to unite with iron, old iron vessels 
 are placed in the water, which become coated with it, 
 and by this means large masses of copper are col- 
 lected. 
 
 Malachite, the splendid green mineral found in 
 Russia, is a carbonate of copper, which is found in a 
 native state, and is quarried out like marble. 
 
 Uses and Tests. Sulphate of copper and its other 
 salts have either a green or a blue tinge, and are 
 much used in the arts and in medicine. Many expe- 
 riments may be tried with solutions of copper, and as 
 they are more or less poisonous, and are, notwith- 
 standing, used to colour pickles, it is desirable to 
 know how to detect its presence. A solution of 
 ammonia gives a deep blue ; hydro-sulphuric acid, a 
 deep black ; prussiate of potash, areddisJi-brown; and if 
 a clean knife or plate of steel be placed in a solution 
 containing much copper, it will be at once precipitated 
 on the steel. 
 
 Sources of Copper. The copper used in England
 
 78 OUTLINES O'F SCIENCE. 
 
 is mostly obtained from copper pyrites in Cornwall, 
 but it is sent across the Bristol Channel to be smelted 
 or separated from its ore. This metal is found in a 
 native state in North America, and is abundant in 
 Australia. 
 
 Other Metals. Didymum, erbium, glucinium, lantha- 
 nium, lithium, norium, terbium, thwium, yttrium, and 
 zirconium, are very rare metals, having qualities and 
 forming compounds similar to those of aluminium, 
 but not of sufficient importance to be noticed in our 
 limited outline of chemistry. 
 
 QUESTIONS ON CHAPTEE XXII. 
 
 How many metallic elements are known ? 
 
 What is aluminium ? What is clay ? 
 
 Of what jewels is alumina the essence ? 
 
 Of what manufacture is it the base ? 
 
 What is antimony ? How does it act with chlorine ? 
 
 What is arsenic ? Where is it generally found ? 
 
 How may the presence of arsenic be detected ? 
 
 What are barium, bismuth, and cadmium ? 
 
 What is calcium ? Where is it found ? 
 
 Of what substances is it the base ? 
 
 What is lime r How is it made ? 
 
 What is cerium ? What are the properties of chromium ? 
 
 By whom is chromium found especially useful ? 
 
 What colours are made from its compounds ? 
 
 What is cobalt ? In what art is it much used ? 
 
 Where is copper found ? Name some of its compounds. 
 
 For what is copper much used ? Why ? 
 
 What compound of copper is found in Russia ? 
 
 Name some tests for copper in solution. 
 
 Where is the English copper found ? Where smelted ? 
 
 Where found in a native state ? 
 
 Name any other rarer metals in this chapter.
 
 CHEMISTRY. 79 
 
 CHAPTER XXIII. 
 
 Gold (aurum) is found in most countries, but only 
 in the metallic state, and generally in grains, or 
 nuggets in quartz, or in small particles in the sands of 
 rivers. It is separated from the sand or from the 
 q lartz when crushed, by washing. 
 
 Carat Gold. Pure gold is of a reddish-yellow 
 colour. The gold of our coinage is mixed with copper, 
 and is called 22 carat gold, because it contains 
 twenty-two twenty-fourth parts of the pure metal. 
 The gold of jewellers contains eighteen of these 
 twenty-fourths, and is therefore called 18 carat gold. 
 It is nearly twenty times heavier than water. 
 
 Electrotyping. The peroxide of gold is much used 
 in electrotyping ; that salt of gold being obtained by 
 dissolving gold in aqua regia, i.e , a mixture of nitric 
 and hydrochloric acids. The value of gold is increased 
 by its wonderful malleability, or capability of being 
 beaten out. 
 
 Iron (ferrum). This valuable metal is found in 
 nearly all parts of the world, either native in small 
 quantities, as magnetic iron ore, as haematite or red 
 oxide of iron, or in its most common and abundant 
 form, as clay ironstone, or some carbonate. 
 
 Pig Iron. Magnetic ore and hematite are easily 
 melted, but the ironstones require an intense heat, 
 and the addition of lime or limestone. The lime com- 
 bines with the clay and sets the metal free ; it sinks 
 to the bottom of the tall furnaces, and is let out 
 boiling into beds of sand, and thus forms pig-iron, or 
 iron in its first stage of manufacture. 
 
 Malleable, or Pure Iron. In this state it is an 
 impure and brittle cast-iron, and if it be required to
 
 80 OUTLINES OF SCIENCE. 
 
 separate the impurities from it, and to render it 
 tough to bear heavy strains, it has to be heated over 
 again once or more, and placed under heavy steam- 
 hammers and rollers, which squeeze out the' carbon, 
 and it is afterwards cut into bars for sale to iron- 
 founders. 
 
 Steel. Cast-iron is converted into steel by heating 
 it for forty or fifty hours in contact with charcoal. 
 The iron absorbs the carbon, and the bars are then 
 heated and welded or hammered together, which 
 increases their tenacity or toughness. Sometimes 
 the process is repeated, and the steel acquires its pro- 
 perty of extreme hardness. 
 
 Silver Steel. By adding one 500th part of its 
 weight of silver, the hardness of steel is greatly in- 
 creased ; but its hardness depends also on the way in 
 which it is cooled after being greatly heated. If it is 
 cooled slowly, it becomes softer, and it is often heated 
 several times, and cooled quickly or slowly as it is 
 required to be hard or soft. This is called tempering 
 the steel. 
 
 Sword Blades. The famous Damascus and Indian 
 sword blades, which have been struck against iron 
 and stone, without breaking, are made by welding 
 pieces of iron and steel together. They are now suc- 
 cessfully imitated by Mr. Wilkinson, of London, 
 whose process of manufacture may be seen in the 
 Museum of Geology, with numerous other chemical 
 and mineralogical curiosities. 
 
 Rust. Iron does not oxidise readily in a dry atmo- 
 sphere, but does so quickly if allowed to get wet. 
 The oxide is what is called rust, and its influence may 
 be observed at the bottom of old iron railings which 
 have not been kept well-painted. 
 
 All the crystals and salts of iron are of a green
 
 CHEMISTRY. 81 
 
 colour, and axe of much use in the ails, as well as in 
 medicine. 
 
 Dyers and ink-makers are indebted to salts of iron 
 for their black colours, and glass bottle makers for 
 their colouring matter. 
 
 Lead is a soft, flexible, and non-elastic metal, which 
 is found in combination with other metals, or in a sul- 
 phuret called galena, from which it is separated by heat. 
 It melts at the low temperature of 612, oxidises 
 quickly on exposure to the air, but the outer coat of 
 rust preserves what is underneath it. 
 
 Type used in printing is formed of three parts lead 
 and one of antimony. Pewter is a compound of lead 
 and tin, and solder also in various proportions, accord- 
 ing as it is required to be hard or soft. 
 
 Rust of Lead. Lead oxidises rapidly when heated, 
 and a grey film is formed on it, which may be seen in 
 any plumber's ladle, and various compounds of lead 
 are used in the arts and in medicine. Painters are 
 greatly indebted to this metal for the white lead, which 
 they use in great quantities, and which is obtained by 
 exposing sheets of lead to the fumes of a vegetable 
 acid such as vinegar. 
 
 Magnesium is a white metal of which the well- 
 known magnesia is the only oxide, and is now exten- 
 sively used to burn in gas where a brilliant white 
 light is needed. It exists abundantly in nature as 
 carbonate of magnesia, and as magnesian limestone. 
 Epsom salts is a sulphate of magnesia. 
 
 Manganese is a greyish-white granular metal, which 
 becomes quickly oxidised by exposure to air, on 
 account of its affinity for oxygen. It is usually 
 found mixed with iron, or some other metal. Its 
 compound, called the black oxide of manganese, is 
 much used in glass-making, and in the preparation of 
 oxygen, and in the arts generally.
 
 82 OUTLINES OF SCIENCE. 
 
 QUESTIONS ON CHAPTER XXIII. 
 
 How and where is gold found ? 
 
 What is eighteen carat gold ? 
 
 How is gold dissolved ? How then used ? 
 
 In what conditions is iron found ? 
 
 How is iron-stone melted ? Explain the process. 
 
 What is pig-iron ? How is it made tougli ? 
 
 What is steel ? Explain the process. 
 
 How is silver steel manufactured ? 
 
 Upon what does its hardness greatly depend ? 
 
 How are the Damascus sword blades made ? 
 
 What causes iron to rust readily ? 
 
 Of what colour are the salts of iron ? 
 
 In what manufactures are they used ? 
 
 What is lead ? \Vhat is galena ? 
 
 Name some properties of lead. 
 
 Of what is printing type composed? 
 
 What is white lead ? How is it used ? 
 
 What is magnesium ? How is it used ? 
 
 How does the oxide of magnesium exist in nature ? 
 
 What is manganese ? How is it usually found? 
 
 How is the oxide of manganese utilised ? 
 
 CHAPTER XXIV. 
 
 Mercury, or Quicksilver, is a brilliant metal more 
 than thirteen times heavier than water, and which 
 has been known from very ancient times. It is gene- 
 rally found in the sulphuret of mercury, which is 
 called cinnabar, but sometimes in combination with 
 gold and silver, and is separated by roasting the ore 
 with lime. 
 
 It is different from all other known metals, in being 
 always in a liquid state at an ordinary temperature of 
 the air, and only becomes solid when exposed to 
 intense cold at 30 below zero. 
 
 Compounds. These are numerous and highly useful
 
 CHEMISTRY. 83 
 
 in medicine, as well as the arts. It is a dangerous 
 metal, as its fumes are injurious to health, and a 
 gentle heat will evaporate it. It easily unites with 
 other metals, and is used in combination with tin to 
 silver looking-glasses. It is also an essential article 
 in the refining of silver. Its compound, calomel, is 
 the sub-chloride of mercury, an active and powerful 
 medicine, and the perchloride called corrosive subli- 
 mate is a deadly poison. Mercury is used in the 
 manufacture of colours for artists and painters. Ver- 
 milion is a compound which is prepared from corro- 
 sive sublimate. 
 
 Tests for Mercury. A solution of its salt gives 
 with ammonia a black precipitate; with iodide of 
 potassium, a greenish yellow ; with chromate of potash, 
 a red. 
 
 As accidents happen at times with corrosive sub- 
 limate, it is well to know that the white of egg is an 
 antidote to it, if swallowed quickly after the poison. 
 
 Nickel is a metal similar in character and uses to 
 cobalt. It is found abundantly in Germany, where 
 the miners call it " nickel kupfer," or false copper. 
 It is white like silver, and is extensively used in the 
 arts. Nickel and brass combined, form German 
 silver. 
 
 Platinum. This is the heaviest of metals, its 
 specific gravity being 21-5. It is found in South 
 America, Eussia, and Ceylon, but at present is only 
 known to exist in small quantities. It will melt 
 under the oxyhydrogen blowpipe, but not with any 
 ordinary heat, and is therefore valuable to form cru- 
 cibles or vessels in which other metals can be 
 heated. 
 
 It does not oxidise or tarnish in either dry or wet 
 atmospheres, and is not injured by the ordinary acids. 
 It is five times the price of silver, but is much used
 
 84 OUTLINES OF SCIENCE. 
 
 in consequence of the characteristics mentioned, and 
 especially in the manufacture of oil of vitriol. 
 
 Potassium. This was discovered in caustic potash 
 by Sir H. Davy, by means of the galvanic battery. 
 It may be procured by subjecting cream of tartar to a 
 great heat. It is of a bluish-white colour, soft like 
 wax, and very brittle. When heated it gives off a 
 green vapour. It has so great an affinity for oxygen, 
 that it must be kept in naphtha in a stoppered bottle. 
 
 It floats on water, and takes fire uniting with the 
 oxygen, and disappearing with a slight explosion. 
 Ou this account it makes a very pleasing experiment. 
 
 Compounds of potassium, namely, potash in various 
 forms, are of great importance in the arts. The prin- 
 cipal are the carbonate, sulphate, and chlorate. The 
 last is a dangerous compound, as it is very liable to 
 explode. It is used in making lucifer matches, and 
 in various detonating mixtures, and has caused the 
 loss of many lives by accident. 
 
 A solution of potash is the base of the various kinds 
 of soap, and it is also used in the manufacture of 
 glass. 
 
 Sodium. This metal is very much like potassium, 
 and was discovered about the same time and in the 
 same manner, by Sir H. Davy. It is light, and has a 
 strong affinity for oxygen ; it will also take fire, if 
 placed on water, but does not burn so rapidly as 
 potassium. It is equally important in art and manu- 
 factures, and is obtained in great abundance from 
 common salt, which is a chloride of sodium. 
 
 Silicon (Si). This metal was discovered in silex, or 
 flint, by Sir H. Davy, and is a dull brown powder, 
 with very little of the metallic in its appearance. 
 Silex, or silicic acid (Si0 3 ), is abundant in the stems 
 and outer parts of all the grasses, in the form of
 
 CHEMISTRY. 85 
 
 silicate of potash, and is the basis of the quartz 
 family. 
 
 Porcelain. Silex is a very important component 
 with alumina in the manufacture of porcelain. The 
 two earths being worked up together with more or 
 less lime and potash, form a plastic clay, which, when 
 shaped and partly baked, is painted with mineral 
 colours which can stand a great heat. This manu- 
 facture has long been known to the Chinese and the 
 people of Japan. 
 
 Glass. This is also a combination of silicates, the 
 finest flints being used for the fine glass, called flint 
 glass on that account. Potash, or soda, causes the 
 fusion or melting of the flint or sand, which is more 
 commonly used, and, like porcelain, it is coloured 
 with mineral oxides ; blue, with oxide of cobalt ; 
 green, with protoxide of copper ; red, by peroxide of 
 iron ; purple, by oxide of gold, &c. 
 
 Oxide of Gold is also used to gild glass, being 
 afterwards burnished. 
 
 QUESTIONS ON CHAPTER XXIV. 
 
 "What is mercury ? Its other name ? 
 
 How is it generally found ? Its weight P 
 
 At what temperature does it freeze? 
 
 Name some of its compounds. 
 
 In what arts and manufactures is it used ? 
 
 With what does mercury give a black precipitate ? 
 
 Why is this metal dangerous ? What is the antidote ? 
 
 What is nickel ? Where is it found ? 
 
 What is its colour, and how is it used ? 
 
 Which is the heaviest of metals ? Where is it found P 
 
 What heat is needed to melt it ? Does it rust ? 
 
 For what purposes is it used ? Its price ? 
 
 Who discovered potassium ? By what means ? 
 
 Describe the properties and affinities of potassium. 
 
 What is said of chlorate of potash ? 
 
 What metal is like potassium in nature and uses ?
 
 86 OUTLINES OF SCIENCE. 
 
 Whence is sodium obtained? Who discovered it? 
 What is silicon ? Of what is it the base ? 
 How is silex employed ? Whence obtained ? 
 Mention the colours that can be made from it. 
 
 CHAPTER XXV. 
 
 Silver, (Ag.) This valuable metal has been long 
 known. It is usually found in combination with 
 other metals, and nearly always with lead. It is 
 separated from the ore by bringing it into contact 
 with mercury. The two metals form an amalgam 
 from which the mercury can be expelled by heat. 
 
 Silver is very soft, and requires to be hardened by 
 18 parts out of 240 of its weight of copper, which is 
 the standard silver of England. It dissolves easily in 
 nitric acid, forming nitrate of silver (N0 5 -f AgO), an 
 extremely corrosive substance, which destroys animal 
 tissues, and is much used in surgery. It is also the 
 chief component of good marking ink. 
 
 All the salts of gilver in contact with animal or 
 vegetable matter, will turn black when exposed to 
 light. They are much used in photography. 
 
 Tin (Stannum), in ancient times called Jupiter. 
 This metal attracted .the enterprising Phoenicians and 
 Carthaginians to the British islands. It is seldom 
 found alone, but usually in combination with ores of 
 copper or zinc. It abounds most in granite veins, 
 when it is called mine-tin. At other times it is found 
 in alluvial deposits in small particles which are called 
 tin-stone, and are of excessive hardness. 
 
 Uses of Tin. This valuable metal has long been 
 known to commerce, and was used as a compound 
 with copper for the making of swords, knives, &c., 
 until the method of working iron was discovered.
 
 CHEMISTRY. 87 
 
 This metal tarnishes quickly, but oxidises or rusts 
 slowly under moisture, and is therefore valuable for 
 protecting other metals, as it is so malleable as to be 
 reduced to extreme thinness, as in tin-foil. 
 
 Compounds of tin are also important in glass and 
 porcelain making, and in dying, as it fixes certain 
 colours on woven fabrics. The Romans bought it to 
 mix with other metal to form their bronze helmets, 
 &c., and numerous old furnaces remain, which prove 
 that in ancient times it was extensively obtained. It 
 was chiefly worked by Jews in the time of the 
 Plantagenets. 
 
 Zinc (Zn.) is found abundantly in France and Ger- 
 many as a zinc blende, a sulphuret, or in calamine, a 
 carbonate of zinc. It is a bluish metal, hard and 
 brittle, which rapidly oxidises when heated in the 
 open air. Its compounds with copper are noticed in 
 the article on that metal. 
 
 The chloride of zinc, i.e., zinc dissolved in hydro- 
 chloric acid, is extensively used as a disinfectant, as it 
 stays the decay of animal matter, and decomposes 
 offensive gases. It is also used to saturate wood, as 
 a protective against the dry rot. Zinc is now used 
 extensively by builders and others, as it does not rust 
 deeply, the oxide which rapidly forms, becoming a 
 protection to the metal beneath. 
 
 QUESTIONS ON CHAPTER XXV. 
 
 i 
 
 How is silver usually found ? 
 
 How is silver separated from its ore ? 
 
 What is called standard silver in England ? 
 
 In what is it easily dissolved ? What is that called ? 
 
 Describe some uses of nitrate of silver. 
 
 In what are compounds of silver much used ? 
 
 What is said respecting their change of colour ? 
 
 Where is tin found ? What was it once called ? 
 
 Name some of its properties and uses, 
 
 82
 
 88 OUTLINES OF SCIENCE. 
 
 How does mine-tin differ from tin-stone? 
 
 Why is it especially valuable to coat other metals? 
 
 For what purpose did the Komans seek it ? 
 
 Where is ziuc found ? In what forms ? 
 
 What is chloride of zinc ? What is its use P 
 
 Name some of its compounds with copper. 
 
 Why is zinc especially useful to builders ? 
 
 Which are the heaviest of the metala ? 
 
 Which are most malleable ? 
 
 Which are most useful in the arts ? 
 
 What metals oxide or rust easily ? 
 
 Which of them resist oxygen best ? 
 
 CHAP TEE XXVI. 
 
 OBGAHTC CHEMISTEY. 
 
 Organic Chemistry treats of those bodies, animal 
 and vegetable, which have organs of inci-ease, repair, 
 and reproduction. Inorganic matter is the nutriment 
 of plants, organic matter that of animals ; grasses and 
 other plants feed on the silex, potash, phosphates, 
 &c., found in the soil, and animals feed on them, so 
 that all living creatures may be said to feed on grass. 
 
 Organised substances contain but few elements ; 
 vegetables consist chiefly of carbon, oxygen, and 
 hydrogen ; animals of carbon, oxygen, hydrogen, and 
 nitrogen. There are some exceptions, as in beetroot, 
 sugar, maple, and unripe fruits, which contain 
 nitrogen. 
 
 Plant Food. The organic matter of the soil, which 
 must consist of decayed vegetable matter, is con- 
 tinually forming carbonic acid, which is absorbed with 
 water by the rootlets of the plant (See Botany). 
 Hence the richness of those virgin soils of the tropics, 
 on which the vegetable matter has been decaying 
 century after century. Light, acting on the carbonic
 
 CHEMISTRY. 89 
 
 acid in plants, decomposes it, and sets free the oxygen. 
 The tropical regions which are so rich in plants, 
 furnish oxygen for the more temperate regions, and 
 to those districts which, destitute of vegetation, are 
 deficient in that element. 
 
 The principal elements of organic chemistry, which 
 we can notice, are the various vegetable acids and 
 their compounds, with the constituents of oils and 
 fats. 
 
 Oxalic Acid, '0 or C.,0 3 . This acid is found in 
 the common sorrel and many other plants, and also 
 in union with lime in the bodies of animals. It is 
 obtained by heating one part potato starch or sugar 
 withy^e parts nitric acid. 
 
 When evaporated, the acid is seen in the form of 
 needle-like crystals. Its solution is a violent poison, 
 for which either chalk or magnesia are antidotes. An 
 oxalate of potash, called salt of lemon, is used to 
 remove iron-mould and other metallic stains from 
 linen. 
 
 Cyanogen, Cy or CLN. This is a colourless gas, 
 which is easily procured from the kernels of almonds, 
 peaches, and other stone fruits, and from bay leaves. 
 It burns with a rose-coloured flame. With hydrogen 
 it forms the powerful liquid called hydrocyanic or 
 pmssic acid, which is so very destructive of life when 
 swallowed or inhaled. 
 
 The combinations of cyanogen are numerous and 
 important in art and manufactures. It is one of the 
 chief elements of success in photography. 
 
 Urea, C 2 N 2 H 4 2 . This element may be obtained 
 from urine, of which it is an important part, or from 
 the union of cyanic acid with dry ammonia. 
 
 Uric Acid, C 10 H 4 N 4 . This acid is found in 
 human urine and in that of all carnivorous animals, 
 
 83
 
 SO OUTLINES OF SCIENCE!. 
 
 birds, reptiles, and many insects. The urine of birds 
 and serpents consists almost entirely of urate of 
 ammonia, and so also does guano, which is the decom- 
 posed excrement of sea-birds. 
 
 This acid has neither colour, taste, nor smell ; it is 
 thought to be the basis of the stones or calculi, that 
 are occasionally found in the human, bladder. 
 
 Acetic Acid, C 4 H 3 3 , or 5. ; common name, vinegar 
 This acid is found in all liquids capable of the vinous 
 fermentation ; the alcohol absorbs oxygen and becomes 
 acid, which it would not do unless it came in contact 
 with yeast. 
 
 Much vinegar is made by mixing poor wine that 
 has become sour, with a little vinegar, and exposing it 
 to the air in casks containing the husks of grapes. 
 Free access of air shortens the process, as the alcohol 
 is more quickly oxidated. 
 
 Pyroligneous Acid. One kind of vinegar is ob- 
 tained by the destructive distillation of wood, which, 
 though less agreeable to the taste, is cheaper, and is 
 capable of being used to preserve meat, to which it 
 gives a smoked flavour. 
 
 Creosote, C U H 2 2 . This is another product of 
 the distillation of wood, which may be obtained from 
 raw pyroligneous acid. It is an oily colourless liquid, 
 with a pungent acid taste, and an odour of smoke. 
 It coagulates albumen, and thereby prevents the 
 putrefaction of animal matters. 
 
 Formic Acid, C 2 H0 3 . This acid, so called from 
 formica, an ant, was formerly obtained from those 
 insects, but may now be had from a mixture of starch 
 or sugar, with oxide of manganese, water, and vitriol. 
 It is a clear, colourless, and caustic or burning liquid, 
 with a strong smell, the vapour of which burns with 
 a blue flame.
 
 CHEMISTRY. 01 
 
 Tartaric Acid, C g H 4 0, or Co. This acid abounds 
 in the juice of the grape, tamarind, and other fruits, 
 and is often found combined with potash on the 
 inside of barrels in which French and German wines 
 have been kept. It is readily obtained by adding one 
 part lime to four parts of cream of tartar, and is very 
 useful in medicine. 
 
 Citric Acid, Ci 2 HjO n . This acid is so similar to 
 tartaric acid that they were thought to be identical 
 until 1784. It is found in abundance in lemon juice, 
 and is of great use in medicine, especially as a preven- 
 tive of scurvy among seamen. It is also largely 
 employed in the manufacture of lemonade, and by 
 calico printers ; it will remove iron-mould from linen, 
 by forming a soluble compound with oxide of iron. 
 
 Malic Acid, C 8 H 4 8 or M. This acid abounds in 
 the juice of apples, to which it gives the sour taste, 
 and is therefore called malic, from mains, an apple- 
 tree. It is also found in other fruits, and in the 
 berry of the mountain ash, from which it may be 
 easily obtained, by saturating their juice with lime. 
 
 Tannic Acid, or Tannin, C 1? H 5 9 or Qt. This 
 acid was formerly called the astringent principle. It 
 is obtained from the bark of the oak, horse chesnut, 
 and other trees, and especially from the gall-nut of 
 the oak-tree. In union with salts of iron it gives a 
 deep colour almost black, and this, suspended in a 
 solution of gum, is the common writing ink. 
 
 But it is of especial service in the manufacture of 
 leather. After the hair has been removed by the 
 action of lime, the hide is steeped for some days in a 
 tank or pit containing bark and water, until the skin 
 becomes changed into leather by the" action of the 
 tanning. 
 
 Sometimes animal bodies have been found whole 
 and tanned in peat bogs, the flesh being preserved
 
 92 OUTLINES OF SCIENCE. 
 
 from putrefaction by the antiseptic quality of the peat 
 juice. 
 
 Gallic Acid, C 7 H0 3 or G. This acid is found free 
 only in the mango fruit, but may be obtained also 
 from the infusion of galls, oak bark, walnut, and other 
 shells. Like tannic acid, it gives a black precipitate 
 with salts of iron. 
 
 It will thus be seen that these various and often 
 exceedingly different compounds are formed from the 
 same elements, carbon, oxygen, hydrogen, and nitro- 
 gen, in different proportions. 
 
 QUESTIONS ON CHAPTER XXVI. 
 
 Of what does organic chemistry treat ? 
 
 Distinguish between the nutriment of plants and animals. 
 
 What plants and fruits do contain nitrogen ? 
 
 What is formed by decaying vegetable matter? 
 
 How is the carbonic acid set free ? 
 
 What are the principal elements of organic chemistry? 
 
 Where is oxalic acid found ? Its symbol ? 
 
 What form do the crystals take ? What are its properties t 
 
 What is cyanogen ? How is it obtained ? 
 
 Name some of its compounds and uses. 
 
 Where are urea and uric acid found ? 
 
 In what substance does it abound ? 
 
 What is acetic acid ? How is it formed ? 
 
 What is pyroligneous acid ? For what is it used ? 
 
 What is creosote ? Name some of its properties. 
 
 From what was formic acid obtained ? 
 
 How is tartaric acid obtained ? Where often found ? 
 
 What acid was thought to be the same thing ? 
 
 How is citric acid employed ? Whence obtained? 
 
 What other acid is found in many fruits ? 
 
 What was once called the Astringent principle ? 
 
 Name some uses of tannic acid. 
 
 Where does it exist in nature ? 
 
 Where is gallic *acid found ? How is it used P
 
 CHEMISTRY. 93 
 
 CHAPTER XXVII. 
 THE VABIOTJS OILS AND FATS. 
 
 Fixed Oils. Oils are either fixed or volatile. The 
 latter can be distilled, but the fixed oils must first be 
 decomposed. They are found chiefly in the cellular 
 tissue of animals, or in the seeds and capsules of 
 plants. Many nuts contain about 50 per cent, 'of oil, 
 linseed 20 to 25 per cent., and hempseed 25 per cent. 
 
 All the fixed oils, while fluid, will leave permanent 
 grease stains on paper. There are some which dry 
 and form a hard coating when exposed to the air, 
 such as linseed oil, nut-oil, and poppy-seed oil ; but 
 olive, almond, and rapeseed oil do not dry when so 
 exposed. 
 
 Spontaneous Combustion. Drying oils, when ex- 
 posed on a large surface, such as shavings or cotton 
 waste, absorb oxygen so rapidly as often to take fire, 
 and produce spontaneous combustion ; on this account 
 great care is required in their use, among any similar 
 light material. 
 
 The fixed oils are soluble in alcohol and turpen- 
 tine, but not in water. 
 
 Glycerine (gluhis, sweet) C,;F 7 5 + HO or GlyO + 
 HO. This is the sweet principle of oils and fats, and 
 is a colourless syrup, which is obtained by heating 
 equal parts of olive or ether oil and fine litharge with 
 a little water, and stirring it until a thick paste is 
 formed. Glycerine is the basis of stearine, margarine, 
 oleine, and other fatty compounds. 
 
 Stearic Acid, CHO, or St. This fatty 'acid is ob- 
 tained from animal fat, and purest from that of 
 mutton. It is of great use in the manufacture of 
 soap and candles. Stearate of soda is the basis of 
 all hard soaps, and stearate of potash the basis of
 
 94 OUTLINES OF SCIENCE. 
 
 soft soap. The acid is used largely in the production 
 of a stearine candle, nearly as good as wax. 
 
 Margaric Acid is very much like stearic, and oleic 
 also, which is the basis of oleine, the chief constituent 
 of the fixed oils. 
 
 Oleine is very useful to oil clocks and watches, be- 
 cause it does not congeal, except at a very low tem- 
 perature. Steam and other engines are greased with 
 more solid substances, on account of the great heat to 
 which they are exposed. 
 
 Butter contains stearine, margarine, and oleine, and 
 three other components, butyrine, caproine, and 
 caprine, which may all be obtained by saponifying the 
 butter, i.e., mixing it with some alkali, and afterwards 
 decomposing it with tartaric acid. 
 
 Spermaceti is found dissolved in spermaceti oil, in 
 the skulls of various kinds of whales. It separates 
 from the sperm oil after death, and is a valuable com- 
 ponent of candles. 
 
 Soap. This is a salt of the fat acids. It has long 
 been known as in use among the barbarian Gauls, by 
 whom it was used to render their hair shining, as is 
 stated by Pliny. 
 
 Hard soaps are made with the fats and fat oils 
 mixed with either soda or potash. Soda gives a 
 harder soap than potash. If oil be used the soap is 
 much softer, so that all the soft soaps are made with 
 the drying oils. 
 
 Soap of potash may be made harder by the addi- 
 tion of common salt, as the chlorine of the salt unites 
 with some of the potash in the soap, and forms chlo- 
 ride of potassium. 
 
 The detergent or cleansing properties of the soap 
 depend on the fact that the neutral stearates, marga- 
 rates, and oleates of potash and soda are decomposed
 
 CHEMISTRY. 95 
 
 by cold and hot water, and an alkali set free, which 
 cleanses the clothes or flesh by forming a soap, with 
 the fatty or dirty matters which soil them. 
 
 Mottled Soap, if genuine, contains salt of copper or 
 of iron, by which it is made harder, and less water 
 than the common kinds. 
 
 Hard Water is made softer by adding carbonate of 
 potash or soda ; where much lime is present the soap 
 is decomposed and wasted, and tends rather to cling 
 to the soiled clothes, than to wash or dissolve the dirt 
 out of them. 
 
 Caoutchouc, also called india-rubber, is obtained 
 from the milky juice of several plants which grow in 
 hot countries. A mould of clay is covered with suc- 
 cessive coats of the juice, which flows from the tree, 
 and hardens outside the mould. It is of a yellowish 
 colour when fresh, but is darkened by the air. 
 
 Beside the common use of caoutchouc as a rubber, 
 it is much used, when dissolved in turpentine, for 
 rendering various fabrics waterproof. It melts at 
 240, and at 600 is dissolved into a vapour, which is 
 again condensed into caoutchisine, the lightest liquid 
 known. This article is used to dissolve oil-colours, 
 and in making varnish, as it dries very rapidly. 
 
 Contraction. Heat contracts it, while it expands 
 almost every other substance ; while being kneaded 
 or punched to render it soft, great heat is evolved ; 
 this may be seen by simply stretching a piece of it, 
 when heat is at once evolved. 
 
 Vulcanite. Heated with sulphur to 300, it com- 
 bines with it, and forms the "vulcanised india-rub- 
 ber " of commerce, which is remarkable for its per- 
 manent elasticity. 
 
 Caoutchouc burns with a bright flame, and in 
 Cayjfline and other places, where it is common, it is 
 usea instead of candles.
 
 96 OUTLINES OF SCIENCE. 
 
 Gutta Percha is the juice of a tree which grows in 
 Borneo, and other East Indian islands, and is obtained, 
 like caoutchouc, by cutting a notch in the tree, from 
 which the juice flows. At a temperature of 212 it 
 becomes soft and plastic, so that it may be used for 
 making mouldings, picture frames, and many other 
 useful articles. Its chief value to the chemist is that 
 it is impervious to water, and resists acids and alkalies, 
 and it is therefore made use of to hoM those articles. 
 
 It is a powerful insulator, or non-conductor of elec- 
 tricity, and is used in great quantities for covering 
 telegraph wires, which, without some such protection, 
 would part with their electricity as they passed under 
 the earth's surface. 
 
 QUESTIONS ON CHAPTER XXVII. 
 
 What is tlie difference between fixed and volatile oils ? 
 
 Where are fixed oils found ? Which will dry ? 
 
 How is spontaneous combustion sometimes caused ? 
 
 In what are the fixed oils soluble ? 
 
 What is the sweet principle of oil called ? 
 
 Of what is glycerine the base ? 
 
 What acid is especially needed for soap and candle* ? 
 
 What other fatty acids are used ? 
 
 What is used for greasing machinery ? 
 
 What substance contains all these acids ? 
 
 What is spermaceti ? Whence obtained ? 
 
 Kow did the Gauls use soap ? 
 
 What eSect have soda and potash on soaps ? 
 
 What is the peculiarity of mottled soap ? 
 
 How may hard water be made softer ? 
 
 What is caoutchouc ? Whence obtained? 
 
 What are the chief uses of india-rubber ? 
 
 What is vulcanised india-rubber? Its use ? 
 
 Where is gutta percha found ? What is it ? 
 
 At what temperature do caoutchouc arid gutta percha melt ? 
 
 Of what special use is it to chemists ? 
 
 Why is it much used in telegraphy ?
 
 CHEMISTRY. 97 
 
 CHAPTER XXVIII. 
 
 Starch, C 12 H 9 9 +2HO. This compound is found 
 in abundance in the cellular tissue of wheat, potatoes, 
 arrow-root, and many other plants, in the form of 
 small white grains of various sizes and shapes. It is 
 easily obtained by scraping the potato into cold water, 
 then pouring off the milky liquor, we find starch 
 among the settlement. 
 
 "When a potato is frozen, the cells which contain 
 the starch are burst by the expansion of the water, 
 and the root becomes so unwholesome, as to be unfit 
 for man or beast. 
 
 To obtain starch from wheaten flour, the flour must 
 be fermented to sourness, that the gluten may sepa- 
 rate from the starch. 
 
 Gum, Ci 2 H u O n . This well-known substance is 
 obtained from the juices of many plants, as gum 
 arabic, &c., soluble in water, and it forms mucilage, 
 which may be precipitated from the solution by alco- 
 hol, and which forms with nitric acid what is called 
 mucic acid. It has not the property of vinous fer- 
 mentation. 
 
 Sugar, C 1C H 9 9 + 2A 9 . This name includes all sub- 
 stances which are capable of vinous fermentation, that 
 is, which are changed by decomposition into alcohol 
 and carbonic acid. 
 
 Cane Sugar is found in the juice of the sugar cane, 
 beet-root, carrot, turnip, potato, and in the nectaries 
 of many flowers. The juices are clarified with lime, 
 and slowly evaporated at a low temperature, when 
 crystals are formed of all the crystallizable matter, and 
 the rest is run off as molasses or treacle. 
 
 9
 
 98 OUTLINES OF SCIENCE. 
 
 Fermentation. This is of several kinds. When 
 starch is changed into sugar it is called saccharine, 
 when sugar is changed into alcohol it is called vinous, 
 and when alcohol is changed into acetic acid, or vine- 
 gar, it is called acetous. When malt liquor is fer- 
 mented without yeast, a mucilage or gum is produced, 
 and it is called the viscous fermentation. When a body 
 undergoes decomposition, with disagreeable odours, it 
 is called the putrefactive fermentation. 
 
 Alcohol, C 4 H 6 2 . This is a very strong volatile 
 spirit, which is obtained in abundance by distillation 
 from brandy, whiskey, and strong wines, but is also 
 found in all the substances that contain starch or 
 sugar. That which is made from damaged grain, con- 
 tains an impure fatty matter, and is very injurious to 
 those who drink it. It has a strong affinity for water, 
 and is never found free from it, except when alcohol 
 has been poured upon quicklime, when the lime will 
 absorb the water contained in the alcohol, and the 
 absolute alcohol will pass off as a vapour. 
 
 Ether is a very volatile fluid, produced by distilling 
 alcohol with an acid. The most common is sulphuric 
 ether, which is prepared by heating alcohol with sul- 
 phuric acid. It is much used in medicine, and has a 
 powerful tendency to remove spasmodic affections. 
 
 Lignine, C J3 H 8 S . This substance forms the tubes 
 and cells of vegetable tissues, and is formed from 
 starch by removing three atoms of its water. It may 
 be easily obtained from sawdust. Flax, when dressed, 
 consists almost entirely of lignine. 
 
 Gun Cotton. This is another remarkable com- 
 pound, obtained in the first instance from starch 
 heated in strong nitric acid. It is now made by im- 
 mersing clean cotton for about fifteen minutes in a 
 mixture of equal parts nitric and sulphuric acids, 
 keeping the cotton entirely covered during the pro-
 
 CHEMISTRY. 99 
 
 cess. The acid is then pressed out, the cotton washed 
 with water, until it no longer reddens litmus paper. 
 It is then dried in a current of air at about 212 of 
 temperature. 
 
 It explodes by percussion or striking, and not by 
 friction, and takes fire at 356 with little smoke. Its 
 force is four times that of gunpowder, and it is much 
 employed in blasting rocks, and in mining operations. 
 
 QUESTIONS ON CHAPTEE XXVIII. 
 
 Of what is starch composed ? Its symbol ? 
 
 How may starch be obtained in a natural state ? 
 
 What is mucilage ? From what obtained ? 
 
 What substances are classed among sugars ? 
 
 What substances are formed by vinous fermentation ? 
 
 Whence may cane sugar be obtained ? 
 
 Describe the process of sugar making. 
 
 Name the various kinds of fermentation. 
 
 What is putrefactive fermentation ? 
 
 How and whence is alcohol obtained ? 
 
 What is contained in alcohol made of bad grain ? 
 
 For what has alcohol a great affinity ? 
 
 How can it be separated from water ? 
 
 What is produced by distilling alcohol with acids? 
 
 What substance forms vegetable tissue ? 
 
 How can lignine be obtained ? 
 
 How is gun cotton made ? 
 
 What will cause it to explode? 
 
 What is its force ? How is it employed ?
 
 100 OUTLINES OF SCIENCE. 
 
 ELECTRICITY. 
 
 CHAPTER XXIX. 
 
 Electricity is the science which treats of that great 
 force in nature, the electric fluid, about which com- 
 paratively little is known. 
 
 From very ancient times philosophers noticed the 
 existence of some attractive power in amber. The 
 Greek philosopher, Thales, of Miletus, called this 
 subtle, unknown spirit, electricity, from eleklron the 
 Greek word for amber. 
 
 Pliny and others wrote of the attractive properties 
 of amber, but do not refer to any further development 
 of the subject, and it was only in the sixteenth cen- 
 tury that Dr. William Gilbert made an attempt to 
 classify some electrical phenomena. 
 
 His experiments led others in the seventeenth cen- 
 tury to continue the study, and Dr. Wall, Newton, 
 Boyle, and many others at home and abroad, down 
 to our own Faraday, have increased the number of 
 facts and experiments in relation to it. 
 
 Electricity is defined as a fluid which seems to per- 
 vade all substances, and which, when undisturbed, 
 remains in a state of equilibrium. In this respect it is 
 similar to heat. 
 
 Vitreous and Resinons Electricity. If a glass tube 
 be rubbed in a flannel, or in a soft dry silk handker-
 
 ELECTRICITY. 
 
 101 
 
 chief, it will attract small balls of dried pith, or pieces 
 of tissue paper. The paper will hang for a moment 
 upon the glass, and then fall off. 
 
 If a light downy feather be suspended by a thread 
 of ichlte silk, and the excited glass be applied to it, the 
 phenomenon will be similar, the feather will cling for 
 a few seconds to the glass tube, and then fall away. 
 If the tube be excited afresh, and again applied to the 
 feather, it will no longer attract it, but will repel it. 
 The feather will move from the glass. But if a stick 
 of sealing-wax be rubbed and applied to the feather, 
 it will attract it. Similarly if the feather be attracted 
 first by sealing-wax, and then repelled by the second 
 rubbing, it will be attracted by presenting a glass 
 tube. On this account it is supposed that there are 
 two kinds of electricity vitreous and resinous. 
 
 The Electroscope. This is an 
 apparatus more or less simple, by 
 which we detect the presence of 
 the electric fluid. It may be 
 made by hanging balls of pith on 
 silk threads, which when applied 
 to the conductor, or any excited 
 electric, will repel each other. 
 The most delicate form is Ben- 
 nett's gold-leaf electrometer, 
 which has two leaves of gold 
 inside a glass jar, attached to a 
 brass knob, and by which the presence of the least 
 quantity may be detected. 
 
 The Heat of Hair. If a quantity of hair be woven 
 and placed on the head of a wooden doll, and the doll 
 fixed on the conductor of a machine, as the cylinder is 
 slowly turned, the hairs on the head of the doll will 
 stand out apart from each other, until something is 
 placed near them to take a portion of their electricity. 
 
 Fig. IS.
 
 102 OUTLINES OF SCIENCE. 
 
 If a boy be placed on a stool with glass legs, and 
 holds a chain attached to the conductor, as the 
 machine is worked, he will become similarly charged 
 with electricity, his hair will stand out, and sparks 
 may be taken from him, while he will feel as though 
 cobwebs were being spread over his face. 
 
 Positive and Negative. Faraday found that when 
 silk is rubbed with glass it becomes negative, when 
 rubbed with sealing-wax it becomes positive, and that 
 in a similar way, in every case of rubbing or excitation, 
 the rubber and the thing rubbed become the one posi- 
 tive and the other negative. On this account it is 
 usual to speak of the vitreous as positive, and the 
 resinous as negative. Bodies positively electrified 
 always repel each other. 
 
 Electrics and Non-electrics. There are some sub- 
 stances, such as those already mentioned, by which 
 electricity can be easily developed ; there are others in 
 which it is very difficult, if not impossible, to do so. 
 
 The latter are called conductors, or non-electrics, and 
 consist of the various metals, their ores and salts, 
 charcoal, all fluids except oil, all saline and earthy 
 substances, smoke and steam. 
 
 The principal electrics or non-conductors are gutta per- 
 cha, glass, amber, sulphur, all resinous substances, wax, 
 silk and cotton, feathers, wool, hair, paper, loaf sugar, 
 dry air, oils and metallic oxides, hard stones, and dry 
 earth. The one kind are conductors, because electricity 
 passes through them, more or less easily ; the other 
 non-conductors, because they do not transmit it. 
 
 Various forms of Electricity. The phenomena of 
 electricity may be produced in several ways, and are 
 therefore known by different names, as Fridional, 
 which is produced by rubbing various electrics ; Mag- 
 netic, which is seen in magnetism ; Thermo-electricity, 
 which is caused by heat ; and Galvanic Electricity, 
 which is the result of chemical action on certain metals.
 
 ELECTRICITY. 
 
 103 
 
 Machines. It 
 is evident that 
 only small quanti- 
 ties of the fluid 
 can be obtained 
 by rubbing glass 
 or sealing - wax 
 with the hand. It> 
 is therefoi'e neces- 
 sary to excite 
 larger surfaces. 
 This is done by 
 the electric machine, which may be of two forms, 
 either a glass cylinder, as in fig. 19, or a circular 
 glass plate. This glass cylinder is so fixed as to press 
 against a rubber, by which means frictional electricity 
 is developed, over a large area. The fluid must be 
 drawn from the earth, and therefore a chain is hung 
 from the rubber to the ground, otherwise the rubber, 
 which is insulated, that is, fixed on a glass support, 
 would not be able to supply the fluid wlien excited. 
 
 The rubber is always negative when excited, and 
 the cylinder positive. A piece of silk passes over the 
 top of the cylinder to the conductor, to help retain 
 the fluid, and the rubber is assisted in its work by an 
 amalgam, formed of tin and quicksilver, which is 
 smeared over it when the friction commences. 
 
 Leyden Jar. It is desirable for 
 various purposes to collect the 
 fluid in quantities, and this is 
 done by a Leyden Jar (fig. 20), 
 or by a battery, when a powerful 
 ehock is required. A glass jar is 
 coated with tinfoil, outside and 
 inside, about two-thirds of the 
 way up. Through the cork or 
 
 wooden stopper a wire or thin 
 
 metal rod is passed, to which a t ;.. 20 .
 
 104 OUTLINES OF SCIENCE. 
 
 small chain is attached, that touches the bottom. 
 When the machine is turned, the electric fluid will 
 pass into the jar, the inside will be positively, and the 
 outside negatively electrified, or the inside will have 
 more, and the outside less, than what is called its 
 natural share. 
 
 Discharger. Any machine which con- 
 ! nects the outside with the inside, will re- 
 store the equilibrium, and for this purpose 
 an instrument is used called a discharger, 
 (fig. 21), with a glass handle. When one 
 knob A is brought near the knob B of the 
 leyden jar, the fluid passes from the inside 
 through the metal conductor to the outer 
 coating of the jar. This fact was first noticed 
 by Cuneus, a Dutch philosopher, who was 
 holding a glass of water, which held some 
 of the electric fluid, and who, Avhen he put his finger 
 into the water, received a slight shock. By using a 
 discharger with a glass handle, the equilibrium may 
 be restored without any shock ; but if one hand be 
 placed on the outside, and the knob B be touched 
 with the other, a violent shock is felt ..as the fluid 
 passes through the arms and upper part of the body 
 to complete the circle. 
 
 QUESTIONS ON CHAPTER XXIX. 
 
 In what siibstance was electricity first noticed ? 
 
 By whom was it first named ? Why ? 
 
 When did Dr. Gilbert classify the phenomena ? 
 
 In what respect is electricity like heat ? 
 
 Name the kinds of electricity. 
 
 How is the vitreous fluid excited? And the resinous ? 
 
 What is the electroscope ? The most delica e form ? 
 
 What happens to a head of hair electrified ?t 
 
 How are the vitreous and resinous states named ? 
 
 What is an electric ? A noa-electric ? 
 
 Name the best electrics. The best conductors.
 
 ELECTRICITY. 105 
 
 Name the various forms of electrical excitement. 
 How is the fluid collected in quantities ? 
 Whence must it be drawn ? By what means ? 
 Describe the electric machine and lejden jar. 
 By whom was the discharging rod invented ? 
 
 CHAPTEE XXX. 
 
 ELECTEICITY continued. 
 
 The Electric Shock. It is a source of great amuse- 
 ment, if instead of a discharger, a number of persons 
 are arranged so as to complete the circuit, one end 
 holding the outside of the jar, and the person at the 
 other end touching the knob at a given signal. The 
 fluid in that case passes through the bodies of all who 
 form the chain, giving a shock of greater or less 
 severity, according to the size of the jar, or the quan- 
 tity of fluid contained. 
 
 The Battery. For experiments in which great 
 power is required, what is called a battery is used. 
 This is composed of several Leyden jars, which are con- 
 nected both within and without, so that they can all 
 be charged or discharged at the same time, and by 
 this means thin wire is heated and even melted, gun- 
 powder and spirits of wine set on fire, and many other 
 similar experiments. 
 
 Darkness and Warmth. By performing electrical 
 experiments in the dark, the various phenomena are 
 seen in greater perfection. As the machine is turned, 
 the fluid is seen to pass round the cylinder to the 
 conductor, and from the conductor to the jar or 
 battery in a stream of bluish fire. 
 
 It is also to be noticed that a warm and dry atmo- 
 sphere is always desirable for the success of electrical 
 experiments, and also that the apparatus be quite free
 
 106 OUTLINES OF SCIENCE. 
 
 from dust as the fluid passes away from the surface 
 quickly, if it be dusty. 
 
 Thunder and Lightning. In hot weather the air 
 becomes overcharged in parts with the electric fluids. 
 Some clouds contain more than their natural share, 
 or are positively electrified. When clouds thus charged 
 come in contact with others containing less than their 
 natural share, the electric fluid passes from one to the 
 other with a flash and an explosion. The flash 
 causes lightning, and the explosion causes the thunder. 
 Many persons dread the thunder, but it is the light- 
 ning which is most to be feared, as it often does 
 damage to trees and tall buildings which are not pro- 
 perly protected. We see the lightning before we 
 hear the thunder, because light travels more rapidly 
 than sound. We may tell the distance of such an 
 electric explosion by noticing how many seconds of 
 time pass between the lightning and its thunder. 
 
 Sound travels at the rate of 1140 feet per second : 
 if we notice, for example, that 12 seconds elapse in the 
 interval between the lightning and the thunder, we 
 may say that the storm is distant from us about 12 
 times 1140 feet, or 13,680 feet, which being divided by 
 5280 feet in a mile, gives a distance of about 2f of a 
 mile. 
 
 Lightning Conductors. It has frequently happened 
 during thunder storms that the electric fluid has struck 
 tall buildings, such as factory chimneys, church steeples, 
 towers, and trees, and ships. On this account it is 
 dangerous to be under tall trees during a thunder 
 storm. 
 
 Dr. Franklin, of America, proved that it could be 
 attracted to the earth by sending up a kite, fastening 
 a key to the lower end of the kite-string, and putting 
 some silk (a non-conductor) between his hand and the 
 key. The fluid was attracted down the string by the 
 key, from which Franklin took sparks in abundance.
 
 ELECTRICITY. 107 
 
 He suggested as a means of preventing accident, that 
 a continuous metal rod should be carried up by the 
 side of high buildings, to be pointed at each end ; the 
 upper end to be tipped with copper, or some other 
 metal which does not rust, because oxides or rusts are 
 bad conductors ; the lower end to be buried in the 
 earth or in a water-tank. By this arrangement, when 
 the fluid passes near the metal point, it is attracted to 
 it, and passes silently down into the earth. 
 
 Blasting Rocks. If a strong charge of electricity 
 be sent through thin wire, it will melt it ; platinum 
 wire is made red-hot by it. The knowledge of this 
 fact is made use of by mining and other engineers to 
 set fire to gunpowder. The powder has a wire 
 passed through it, which is connected at either end 
 with an electrical apparatus. On a given signal the 
 circuit is completed, and the platinum wire inserted 
 in the powder becoming red-hot, the powder is ex- 
 ploded, without danger to those who are performing 
 the experiment. It may be sent any distance, if the 
 conducting wire be properly insulated, as it may be, 
 by coating it with gutta percha. 
 
 QUESTIONS ON CHAPTER XXX. 
 
 Describe what is called an electric shock. 
 
 What is the cause of the shock ? 
 
 What is an electric battery ? It3 uses ? 
 
 How is the brilliancy of experiments increased ? 
 
 What atmosphere is most favourable ? 
 
 What natural phenomena are caused by the electric fluid P 
 
 Why is lightning to be feared rather than thunder ? 
 
 How may its distance be discovered ? 
 
 At what rate do sound and light travel ? 
 
 Has lightning ever been brought to earth ? 
 
 State by whom and in what manner ? 
 
 What is the effect of lightning on tall objects ? 
 
 How can such accidents be prevented ? 
 
 How is electricity made useful ? 
 
 What wire is used ? Describe the process.
 
 108 OUTLINES OF SCIENCE. 
 
 CHAPTEE XXXI. 
 
 GALVANISM. 
 
 GALVANISM and Electricity, if not the same thing 
 produced by different means, are certainly intimately 
 connected. Electricity is always produced by friction 
 of some kind, while Galvanism is the result of chemical 
 action only. 
 
 If a half-crown or a silver plate be placed upon the 
 tongue, and a similar plate of zine under the tongue, 
 on bringing the metals into contact, there is a dis- 
 agreeable acid taste produced. This is galvanism in 
 its simplest form. 
 
 How Produced. If plates of copper and zinc be 
 soldered together in such order that each plate of 
 zinc is connected with each plate of copper, and the 
 connected plates be placed in vessels containing dilute 
 acid, there will be an instant development of chemical 
 action, and galvanic electricity is the result. 
 
 It is to be noticed that the latter is much less 
 powerful in its action than frictional electricity, so 
 that to produce any notable effects, batteries of con- 
 siderable size, and containing numerous pairs of plates, 
 are necessary. 
 
 When the zinc plate is placed in the battery, the 
 acid does not act perceptibly upon it, until a plate of 
 copper or platinum be also introduced, and the two 
 brought into contact, which may be done by connect- 
 ing them with a wire outside the battery. The cir- 
 cuit being completed, the zinc is at once oxidated by 
 the acid, and becomes negative^ while the other plate 
 is positive, and the galvanic fluid flows from the posi- 
 tive to the negative.
 
 GALVANISM. 
 
 109 
 
 Fig. 22. 
 
 Size of Plates. It is remark- 
 able that the intensity of the 
 action does not depend much 
 on the size of the plates, but on 
 the number of the circuits. A 
 tiny battery may be made in a 
 thimble with the two metals and 
 a little salt and water, but when 
 great energy is required, a num- 
 ber of cells must be placed side 
 by side, and connected by slips 
 or vires of copper or any other 
 good dry conductor. 
 
 Galvani. The philosopher, Galvani, who was the 
 discoverer of the science, was professor of Anatomy 
 at Bologna, about 1790, and he who first noticed the 
 fluid did so, as we are accustomed to say, by accident. 
 He was performing some experiments on frictional 
 electricity, when he or his wife noticed that a small 
 quantity of the electric fluid sent through the nerves 
 of a frog, produced a violent agitation or convulsion 
 of the muscles. He tried various experiments on ani- 
 mals, both living and dead, some of which were very 
 cruel, but which plainly proved that the passage of the 
 fluid through the nerves caused a shock to the nervous 
 system. 
 
 The Leech. A simple example of its effect may be 
 seen by placing a leech on a piece of copper, and 
 making it also touch a piece of silver. So often as it 
 touches both metals, it receives a shock, and a con- 
 tinuation of such shocks will kill the leech. 
 
 Voltaic Piles. Other experiments were tried by 
 Volta, who was a professor at Pa via, in Italy, and 
 from whom galvanism is sometimes called voltaic 
 electricity. 
 
 10
 
 110 
 
 OUTLINES OF SCIENCE. 
 
 He formed what is called a voltaic pile, by 
 placing discs of silver and of zinc in a pile, 
 with cards soaked in dilute acid placed be- 
 tween each, as in fig. 23, where the lines 
 represent plates of silver and zinc, and 
 the card or cloth soaked in salt water, or 
 dilute acid, and placed between them. By 
 touching the lowest plate and the uppermost 
 at the same time, a shock was received, 
 which was repeated every time the circle was 
 thus completed. 
 
 Advantage of Galvanism. The electric fluid pro- 
 duced by galvanic action is of most use, because, 
 though its action is less intense, it is continuous and 
 apparently inexhaustible, while that developed by 
 frictional electricity, however intense it may be, is 
 discharged instantaneously. For example, if it be 
 required to decompose a drop of water into its original 
 elements, oxygen and hydrogen, it will require a very 
 powerful shock of frictional electricity to perform it, 
 but by means of a suitable instrument, the positive 
 and negative wires of a galvanic battery may be in- 
 troduced into water, and so long as the circuit re- 
 mains completed, the water will be decomposed, the 
 hydrogen will quickly ascend from the negative pole 
 to the upper end of the tube, while the oxygen will 
 collect in bubbles on the inside of it. The knowledge 
 of this fact has enabled experimenters to provide those 
 gases at a cheap rate, and to store them in gasholders, 
 until they require to use them for experiments, or to 
 give intensity to the light required in the exhibition 
 of dissolving views, or of the oxyhydrogen microscope. 
 The action is quickened by adding a little sulphuric 
 acid to the water. 
 
 The Reduction of Metals. If the tube be filled 
 with a solution of acetate of lead, the gas will not be
 
 GALVANISM. ill 
 
 perceived to pass from the negative pole, but small 
 metallic spikes like needles are formed on the negative 
 wires. If the battery be powerful, and the tube con- 
 tains a strong solution, as the process continues the 
 lead is reduced or separated, and a small fern-like or 
 tree-like mass of metallic spikes is the result. 
 
 Electrotypes. The fact just noted, i.e. that the 
 hydrogen from the negative pole separates metals 
 from their oxides, has led to the process which is 
 called electrotyping. A solution of the oxide of the 
 required metal has to be placed on the vessel, and the 
 object which is required to be coated with the metal 
 is placed in contact with the negative pole ; so soon 
 as the circuit is formed, the metal begins to be de- 
 posited on the surface of the articles to be coated. In 
 this way spoons, forks, dishes, &c., are plated with 
 silver, while any object, such as medals, coins, casts, 
 may be copied, as the finest lines are reproduced upon 
 the deposited metal. 
 
 Galvanized Iron and Tin. If sheets of iron or iron 
 wire be placed in a solution of sulphate of zinc, and ex- 
 posed to galvanic action, the zinc will be deposited on 
 the iron, and what is called galvanized iron is pro- 
 duced. This is very useful, as being less b'able to 
 oxidation or rust than the unprotected iron. 
 
 The iron may be tinned in a similar manner, by 
 placing it in a solution of oxide of tin. 
 
 QUESTIONS ON CHAPTER XXXI. 
 
 Describe how galvanism and electricity are produced. 
 What simple experiment developes galvanism ? 
 How is it produced on a larger scale? 
 On what principle is the battery formed? 
 Of the metals employed, which becomes positive f 
 What is said about the intensity of the action ? 
 How was the influence of galvanism discovered ? 
 Show how a leech can be affected by it. 
 
 10- 2
 
 112 OUTLINES OF SCIENCE. 
 
 What is the principle of the voltaic pile? 
 
 What are the peculiar advantages of galvanism P 
 
 What are its ell'ects on water ? 
 
 How may the action be increased ? 
 
 If a metal be contained in the solution, what occur*? 
 
 To what process has this led ? Describe it. 
 
 How is iron galvanized ? 
 
 CHAPTEE XXXII. 
 
 MAGNETISM. 
 
 MAGNETISM is a peculiar property which exists in an 
 oxide of iron, called loadstone, to attract iron and steel, 
 and which property it communicates freely to iron in 
 any form by contact or friction. It was first dis- 
 covered at Magnesia, in Asia Minor, and has henceforth 
 been called magnetes. It is now found in Norway 
 and Sweden, in Elba, and in some parts of Asia. 
 
 Directive Power. It is of especial use to man for 
 what is called its directive power, which has an in- 
 variable tendency to arrange itself in a certain posi- 
 tion with respect to the poles of the earth. 
 
 If a small magnet, or a steel needle rubbed with a 
 magnet, be suspended or allowed to turn on a pivot 
 freely, it will always point north and south. The 
 knowledge of this fact has been made use of by mari- 
 ners since the middle of the thirteenth centmy, and 
 ships are now steered across the pathless ocean by the 
 aid of the mariner's compass. Since that time nearly 
 all the important discoveries have been made by 
 navigators, who without the compass could never have 
 pursued the extensive voyages which are now common. 
 
 Nature of Magnetism. It is of two kinds, like the 
 electric fluid, and every magnetic bar or horseshoe has 
 its two poles at the extremities. 
 
 Similar poles repel ; those in opposite states attract
 
 MAGNETISM. 113 
 
 each other. Its attraction is exercised in curves, as 
 may be seen by scattering iron filings on a sheet of 
 paper placed over a good magnet ; they will form them- 
 selves into curves, of which one of the poles will be a 
 centre. 
 
 A bar of soft iron, kept for some time in an upright 
 position, becomes magnetic, and it may also be ren- 
 dered magnetic by an electric shock. 
 
 A magnet loses nothing of its power by being used 
 to rub or to attract others, but rather gains, and the 
 power may be immensely increased by welding to- 
 gether a number of smaller magnets, just as the in- 
 tensity of galvanic electricity is increased more by 
 multiplication of cells in a battery, than by the size 
 of the plates which are exposed to chemical action. 
 
 Dip and Variation of Compass. If a small bar of 
 steel, which exactly balances on a pivot, be magnet- 
 ised, its balance is destroyed, and it will make an 
 angle with the horizon ; this is called the dip, or de- 
 pression of the needle, and is continually changing. 
 
 As the magnetic axis of the earth does not coin- 
 cide, or run in exactly the same line with the 
 terrestrial axis, the needle does not point due north 
 and south, but at present 24 west of north. As this 
 direction is continually changing, it is called the 
 variation of the compass. 
 
 Mariner's Compass. The compass is generally a 
 circular, shallow metal box, at the bottom of which is 
 a card, in the centre of which is a point on which the 
 needle is fixed. The card is divided into thirty-two 
 equal parts, by Hues called rhumbs, or points. The 
 needle is formed into a rhomboid at each end, and 
 over all is a plate of glass, to preserve it from the 
 weather and wind. 
 
 Electro-Magnetism. It was demonstrated by Oer- 
 sted in 1820 that any conductor would exhibit the 
 
 103
 
 114 OUTLINES OF SCIENCE. 
 
 properties of the magnet, if it were made to form part 
 of the circle between the poles of the galvanic battery. 
 If the conducting wire of a battery be coiled round 
 a bar of soft iron, while the current passes the bar 
 will be magnetised. This is an electro-magnet ; by 
 increasing the number and direction of the coils we 
 increase the power of the magnet, and especially if the 
 wire be carefully covered with silk. Bars of iron are 
 rendered soft, as it is called, by being heated to red- 
 ness, and allowed to cool gradually. Some magnets 
 have been made so powerful, that they would support 
 a ton weight. 
 
 QUESTIONS ON CHAPTER XXXII. 
 
 What is magnetism ? When first known ? 
 
 What is the directive power of magnetism ? 
 
 How will it always point ? 
 
 What is the advantage of this tendency ? 
 
 In what respect is it like electricity ? 
 
 How may a bar of soft iron become magnetic ? 
 
 How may the power of magnets be increased ? 
 
 What is the dip of the needle ? 
 
 How does the magnetic needle exactly point P 
 
 Why does it not point due north ? 
 
 What is the variation of the compass P 
 
 Describe the mariner's compass. 
 
 What is an electro-magnet ? 
 
 How may the power of it be increased? 
 
 What is a bar of soft iron ? 
 
 What is said of the power of magnets t
 
 GEOLOGY. H5 
 
 GEOLOGY. 
 
 CHAPTER XXXIII. 
 
 GEOLOGY (from ge, the earth, and logos, a discourse) 
 is the science which treats of the internal structure of 
 the earth, and the materials of which it is composed. 
 
 Those who are content with what they see on the 
 surface, may think that the various substances which 
 belong to the crust of the earth are arranged without 
 any regard to order or design, but the fact is quite 
 otherwise. Where no artificial or natural disturbance 
 has been made, these materials are always found in a 
 certain order of succession. 
 
 Earths. The outer crust is composed of various 
 earths, which consist either of decayed vegetables 
 and plants, or of crumbled or disintegrated rock of some 
 kind. Hard rocks, when exposed to the weather, are 
 gradually disintegrated, or crumbled into small pieces. 
 The chief are Silex, or flint, which produces siliceous 
 earth, or sand ; Calx, or limestone, which produces 
 calcareous or chalky earth, and Argilla, or clay, which 
 produces the clayey earth, of which pottery and bricks 
 are made. 
 
 No one of these alone is sufficient for the purposes 
 of cultivation. Clay alone would not allow the water 
 to drain through it, because its particles adhere so 
 closely together ; chalk or silex alone would fail, for
 
 116 OUTLINES OF SCIENCE. 
 
 the opposite reason ; the water would filter through 
 them so quickly, that they would nearly always be dry. 
 Each of the earths in its separate form is of great use 
 in other respects. 
 
 Earth Uses. Silica is the basis of the glass manu- 
 facture, and calx in the manufacture of soaps, sugar, 
 &c., as well as being essential to the builder, in the 
 various forms of lime and cements. 
 
 In some cases, as in the building of houses, all these 
 materials are required, and at times the farmer uses 
 chalk and sand to warm or to lighten the stiff clay 
 soils of low-lying districts. 
 
 Proportions. It is found that these earths are 
 to be found in the crust of the earth in the following 
 proportions : silex, or flint, about one half; argilla, or 
 clay, one sixth ; and calx, or lime, one eighth. 
 
 Other simple minerals, such as mica, hornblende, 
 spar, talc, chlorite, and iron in its various forms. 
 
 All the quartz rock, and all the sand on the sea- 
 shore is silex ; all the shells and corals, and nearly 
 all the bones of animals are calx. 
 
 Lime is seldom found pure, because it has so great 
 an affinity or liking for carbonic acid, that it is al- 
 most always in union with it, and is called carbonate 
 of lime. 
 
 Rocks. When we have dug through the earths, we 
 come to harder materials, called rocks, and lying 
 usually in beds or strata. These are of materials 
 similar to those which compose the earth, but in a 
 compact or solid form. 
 
 From the accompanying diagram will be seen the 
 various positions of the rock strata or beds, in the 
 order in which they are invariably found, unless dis- 
 turbed by certain convulsions, to be noticed hereafter. 
 Natural examples of this may often be seen in sea-side 
 cliffs, in railway cuttings, and steep embankments.
 
 GEOLOGY. 
 
 117 
 
 Vegetable Soil. 
 Clay, Sand, and Gravel. 
 Diluvial Clay, with Boul- 
 ders. 
 
 Sandstone and Grits. 
 
 Marls, Imperfect Lime- 
 stone. Gypsum. 
 
 Blue and Plastic Clays, 
 Marls, and Lignites. 
 
 if 
 
 9i 
 
 53 r 
 
 fi 
 
 B I 
 
 Chalk Beds with Fliuts or 
 
 without. 
 Green Sands and Gault. 
 
 Wealden Clay.Limestones, 
 
 and Sand. 
 
 Oolitic Limestone & Grits. 
 Lias Limestone & Shales. 
 Saliferous Marls. 
 New Red Sandstone. 
 Magnesian Limestone. 
 
 Coal Beds, alternating with 
 Sandstone, Shale, Iron- 
 stone, and impure Lime- 
 stone. 
 
 Carboniferous Limestone. 
 
 Quartoze Sandstone. 
 Old Red Sandstone. 
 
 
 
 Silurian Limestones. 
 
 Grauwacke" Rocks and 
 Sandy Slate. 
 
 Clay, and other Slates. 
 Mica/Talc, & other Schists. 
 
 Gneiss, Quartz, and Crys- 
 talline limestone. 
 
 Granite and other Plutonic Bock*
 
 118 OUTLINES OF SCIENCE. 
 
 Unstratified Rocks. Under the lowest strata of 
 rocks we come to those of igneous formation, some- 
 times called Plutonic rocks, and sometimes volcanic, 
 because the materials of which they are composed have 
 been evidently fused by heat, or mixed together while 
 in a fluid state as lava is when poured from a volcano. 
 On this account Humboldt and other geologists called 
 them rocks of eruption. 
 
 Unlike those which lie above them, they have no 
 strata, while all that lie above the Plutonic have evi- 
 dently been slowly deposited from above, and in a 
 fluid state also. 
 
 The Plutonic rocks consist of granite, trap rock, and 
 volcanic rock. Of these granite is the lowest and 
 hardest, and forms a very durable but very expensive 
 building stone. Trap rock appears to be more recent 
 than granite, and the volcanic rock more so than the 
 other tAvo. 
 
 The trap rock, so called from trappa, the Swedish 
 word for a stair, is found in great abundance in 
 Northern Europe, often in a series of stairs or projec- 
 tions, and sometimes in the form of columns or pillars, 
 as at the Giant's Causeway, in the north of Ireland, 
 and Fingal's Cave, in Staffa. 
 
 The various kinds are called basalt, greenstone, 
 claystone, porphyry, and amygdaloid (almond-like), 
 which contains fragments of various stone and mine- 
 ral, scattered about it like plums in a pudding, or 
 almonds in a cake. 
 
 Volcanic rocks are less crystalline and compact, and 
 are called lava, obsidian, scoriae, tufa, and pumice 
 stone. 
 
 QUESTIONS ON CHAPTER XXXIY. 
 
 Wliat is geology ? 
 
 Of what is the crust of the earth composed ? 
 
 Wiiut happens when rocka are exposed ?
 
 GEOLOGY. 
 
 What are the chief earths ? 
 
 In what proportions are they found ? 
 
 Of which are pottery and bricks made ? 
 
 Of what is silica the basis ? 
 
 In what manufactures is calx used ? 
 
 What use does the farmer make of chalk ? 
 
 How is linie usually found ? 
 
 How do the rocks lie ? 
 
 Where do we see proofs of this ? 
 
 "What is found under the stratified rocks ? 
 
 Describe the nature of Plutonic rocks. 
 
 What does Humboldt call them ? 
 
 In what state have strata been deposited ? 
 
 Which is the hardest known rock ? 
 
 What is trap rock, and where is it found ? 
 
 What is amygdaloid ? 
 
 To what kind do lava and pumice stone belong t 
 
 CHAPTER XXXV. 
 
 Primary Rocks. The primary rocks, which are the 
 lowest stratified rocks, are so called because they con- 
 tain no animal or vegetable remains, and are there- 
 fore supposed to have been deposited before the exist- 
 ence of plants or animals. 
 
 They do not contain any fragment of other rocks, 
 are very hard and compact, and are slaty and crystal- 
 line in appearance, which is thought to be the result 
 of the intense heat to which they were at some time 
 subject, through contact with the Plutonic rocks. 
 
 The principal of these series are gneiss, which is 
 much like granite, mica, talc, and other schists or 
 plates, quartz rock, crystalline, limestone, and clay 
 slates. 
 
 Metamorphie. In consequence of the crystalline 
 appearance and texture of these rocks, some geolo- 
 gists have called them metamorphic, and they have
 
 120 OUTLINES OF SCIENCE. 
 
 doubtless been to some extent changed by intense 
 heat. 
 
 Transition Rocks.- -The series above the primary 
 contains a few fossil remains of plants, animals, or 
 zoophytes, and marine shells, and as they are therefore 
 thought to have been deposited between the primary 
 and the secondary, they are called transition rocks. 
 
 These consist of thick beds of sandstone, shale, or 
 hardened mud, slate, and limestone, and are known as 
 Cambrian, Silurian, or Greywacke strata. 
 
 These abound in Shropshire, the country of the 
 ancient Silures, in Wales, and in Scotland, hence their 
 names. They contain quantities of silver, copper, 
 and lead, in Wales and Scotland ; blacklead, in Cum- 
 berland ; and quicksilver in Spain. 
 
 Secondary Rocks. The rocks of this formation in- 
 clude four great systems, and numerous sub-divisions 
 or groups. The great systems are the CARBONIFEROUS, 
 or coal-producing ; the SALIFEROUS, or salt-bearing ; 
 OOLITIC, or egg-like ; and the CRETACEOUS, or chalky 
 systems. 
 
 The Carboniferous group includes the old red sand- 
 stone, the mountain limestone, and the various seams 
 or beds of coal, alternating with shale, ironstone, sand- 
 stone, and impure limestone. 
 
 The Saliferous system includes magnesian lime- 
 stone, the new red sandstone, and the shell limestone 
 and marls. 
 
 The Oolitic system includes the lias, or stratified 
 limestone, the oolitic limestone, and the wealden clay ; 
 and under the Cretaceous, or chalk system, the lower 
 green sand, gault, upper green sand, and chalk. 
 
 TJnstratified Rocks. Seeing that granite, moun- 
 tain limestone, and others, lie so deeply buried under 
 the surface of the earth, inquirers will ask how it is 
 that in Scotland and many other places, these rocks
 
 GEOLOGY. 121 
 
 form high mountains, towering far above the strata 
 which are said to lie above them. 
 
 This state of things is caused by the bursting forth 
 of the igneous rocks, through the overlying stratified 
 beds, a convulsion which must have occurred, or we 
 should never see granite and other of the un stratified 
 rocks in Scotland and elsewhere, where whole moun- 
 tain ranges are composed of that material. But 
 though the granite has been driven through the upper 
 strata, if the granite were taken suddenly away, the 
 various beds would come into line again, and the one 
 side of the strata would match the other side. 
 
 Unvarying order prevails through all the series as 
 to position. We never find chalk below coal, nor coal 
 below slate, and so on. 
 
 There may be a series in which some rocks are ab- 
 sent, as is the case where coal or chalk are sometimes 
 found lying immediately upon slate, without the 
 intervention of sandstone or limestone. But never, 
 in any case, is the order found reversed, so that a 
 geologist would never seek coal below old red sand- 
 stone or Greywacke. 
 
 QUESTIONS ON CHAPTER XXXV. 
 
 Where are the primary rocks found ? 
 
 Give some description of them. 
 
 Bj what is their crystalline appearance caused? 
 
 Name the principal primary rocks. 
 
 By what other name are they called ? 
 
 What series lies above the primary ? 
 
 What remains does it contain ? 
 
 Of what do transition rocks consist ? 
 
 What are the Silurian, and where found? 
 
 What minerals do they contain ? 
 
 What systems form the secondary rocks ? 
 
 What are the carboniferous rocks ? 
 
 To which do chalk and marls belong? 
 
 Explain how granite is found at the surface. 
 
 What is said of the order in which rocks lie ? 
 
 Wkere is granite found in abundance P 
 
 11
 
 122 OUTLINES OF SCIENCE. 
 
 CHAPTER XXXVI. 
 
 Tertiary Formation. Above the chalk system we 
 find three groups of rocks in regular succession, called 
 Eocene, Miocene, and Pliocene, and which are chiefly 
 deposited in basins or hollows, being evidently of 
 more recent formation than those of which we have 
 spoken previously. 
 
 Eocene. The Eocene, or lowest of the Tertiary 
 strata (from eos, dawn, and kainos, new or recent), is 
 so called because the remains of animals which are 
 found in it are similar to those of animals which now 
 exist. It is therefore called the dawn of a new period. 
 Out of one hundred species of fossils, nearly four per 
 cent., or four in every hundred, are like those of 
 existing species. 
 
 Miocene. In the Miocene (from melon, less) this 
 number increases from four per cent, to seventeen. 
 
 In the Pliocene, or more recent (from pleios, more), 
 the number of extant species amounts to nearly fifty 
 per cent., and in the upper strata, or new pliocene, 
 more than ninety per cent., that is, out of one hundred 
 fossil animals, ninety or more are similar to those 
 which now exist. 
 
 Proofs of Design. There are persons who teach 
 that all creation is governed by natural laws, which 
 operate of themselves. Geology, which is sometimes 
 called the " Great Stone Book," teaches that there 
 was a time when man did not exist, and that other 
 animals lived before him. Man must therefore have 
 been created, as the Book of Genesis declares, after 
 other animals. His Creator must be self-existent, 
 uncreated, everywhere present, acting and ruling. 
 Such a creator is God alone.
 
 GEOLOGY. 123 
 
 The Tertiary rocks consist of marls, a composition 
 of clay and chalk, in which there is more clay than 
 chalk, gypsum, or plaster of Paris, loose limestone 
 and sandstone, lignite, or half-formed coal, blue and 
 other plastic clays. 
 
 Eocene beds were found in England and France, 
 miocene beds in France, Germany, and other parts of 
 Europe, but not in England, and pliocene in various 
 parts of Great Britain and Ireland. London and 
 Paris are built on eocene basins, and consequently 
 there is an abundance of good clay in the vicinity of 
 the one, while gypsum is found in great quantities in 
 the neighbourhood of Paris. 
 
 Eocene Fossils. In this system it is very remark- 
 able that more than 1200 species of fossil shells have 
 been found, only about 40 of which are now known 
 to exist. 
 
 Of forty large quadrupeds, the remains of which 
 have been found, and some of which are as large as 
 the horse and the rhinoceros, there are only four 
 living species at present in existence, and of these 
 three are of the tapir tribe. Some of large size have 
 been found in the Isle of Wight. From the great size 
 of these remains, it is evident that the vegetation of 
 the part of the world which they inhabited was of a 
 tropical character, as both monkeys and palm trees 
 have been found, as well as fossil elephants, hippo- 
 potami, and others of the pachydermatous, or thick- 
 skinned animals, and turtles. 
 
 It is also seen that the beds of lignite contain re- 
 mains of such vegetation as would be required by 
 creatures of that growth. 
 
 Miocene Fossils. There are none of these in Eng- 
 land, but at Epplesheim, in Hesse Darmstadt, Ger- 
 many, numerous very large fossils have been discovered 
 of an animal similar to the tapir, and the largest of
 
 124 OUTLINES OF SCIENCE. 
 
 all which has yet been found. It has been called the 
 dinotherium. The head alone measures four feet in 
 length, and three in breadth, and is furnished with 
 huge tusks bent downwards. 
 
 Pliocene Fossils. The pliocene fossils are found 
 in the glacial drift of Norfolk, in North Wales, and on 
 the Clyde, in Scotland. There are also specimens 
 found in Yorkshire, notably in a cave at Kirkdale, 
 where the bones of 300 hyenas were found, as well as 
 those of the elephant, hippopotamus, horse, bear, wolf, 
 and several birds, in all more than thirty different 
 species. 
 
 QUESTIONS ON CHAPTER XXXVI. 
 
 What rocks are found above the chalk ? 
 
 Of how many groups do tertiary rocks consist? 
 
 Which is the lowest ? What does it contain ? 
 
 Why is the eocene system so called ? 
 
 What is peculiar to the pliocene group ? 
 
 Of what do the tertiary rocks consist r 
 
 Where are eocene beds found ? 
 
 Which are not found in England ? 
 
 What is said of London and Paris ? 
 
 What is gypsum ? Where is it found ? 
 
 In what groups have large quadrupeds been found ? 
 
 In what island are some of them found ? 
 
 What is said of the vegetation of the time ? 
 
 Where are miocene fossils found ? 
 
 What are the largest of them called ? 
 
 Where are the pliocene fossils found ? 
 
 What wore found in Kirkdale Cave ?
 
 GEOLOGY. 125 
 
 CHAPTER XXXVII. 
 
 THE following tabular arrangement, which is gene- 
 rally agreed upon by geologists, will be useful for 
 reference. 
 
 There are ten systems, as follows : 
 
 I. The Post-tertiary system, consisting of all earthy 
 
 deposits, peat-mosses, coral-reefs, raised beaches, 
 and containing remains of plants and animals of 
 existing species, or of species recently extinct, or no 
 longer existing. 
 
 II. The Tertiary system, embracing all the regularly 
 
 stratified clays, marls, limestones, and lignites, 
 which are found above the chalk, and containing 
 remains of plants and animals mostly extinct, but 
 similar to existing species. 
 
 III. The Cretaceous, or Chalk system, comprising all 
 the chalk and greensand beds, and containing 
 remains of plants and animals, chiefly marine, and 
 all extinct. 
 
 IV. The Oolitic, consisting of the Wealden, oolitic, 
 and lias strata, and containing plants and animals 
 chiefly reptiles, and all extinct. 
 
 V. The Triassic, or Triple system, including (1) the 
 
 saliferous marls, (2) muschelkalk, or shelly lime- 
 stone, and (3) the variegated sandstones, Avith 
 remains similar to the oolitic. 
 
 VI. The Permian, including lower portion of the new 
 red sandstones and magnesian limestone, with 
 plant and animal remains, similar to those found 
 in the carboniferous system. 
 
 VII. The Carboniferous system, embracing the coal 
 formations, mountain limestone, ironstones, and 
 carboniferous slates. It has abundant remains 
 
 113
 
 126 OUTLINES OF SCIENCE. 
 
 of plants and animals, the plants being nearly all 
 endogenous (see Botany) in the coal, and the ani- 
 mals in the limestone all marine shells, fishes, and 
 zoophytes. 
 
 VIII. The Old Red Sandstone, or Devonian system, 
 including the yellow sandstone, red conglomerate, 
 and grey flagstone groups. Some remains of 
 fishes, Crustacea, and shell-fish, but very few plants. 
 
 IX. The Silurian system. It contains numerous re- 
 mains of marine invertebrate animals. 
 
 X. The Primary, or Metamorphic system, containing 
 
 all hard and crystalline rocks, and quite destitute 
 of fossils. 
 
 These have also been arranged in four periods, in 
 accordance with the fossils found therein : 
 I. The Cainozoic, or those of recent life. 
 II. The Mesozwc, or those of middle life. 
 
 III. The Palaeozoic, or those of ancient life. 
 
 IV. The Azoic, or those void of life, or destitute of 
 fossils. 
 
 QUESTIONS ON CHAPTER XXXVII. 
 
 How many systems does the tabular arrangement contain ? 
 
 Name the first and the tenth. 
 
 What remains does the post -tertiary centain ? 
 
 What rocks are included in the permian ? 
 
 What system is found above the chalk ? 
 
 Which contains extinct animals, but similar to existing species ? 
 
 Which contains marine animals all extinct ? 
 
 What rocks are included in the triassic system ? 
 
 In which system are coal and iron found ? 
 
 What plants are found in the carboniferous system ? 
 
 What system is quite destitute of fossils ? 
 
 In what formation are huge reptiles found ? 
 
 What is peculiar to the metamorphic rocks F 
 
 Name the four fossil periods. 
 
 What is meant by the azoic 1
 
 HEAT. 127 
 
 HEAT. 
 
 CHAPTER XXXVIIL 
 
 Definition. Heat has been defined as " the essence 
 that gives warmth, and which preserves gases and 
 liquids from becoming solid." 
 
 Heat which is felt on approaching a fire is called 
 sensible, that which has to be produced by mechanical 
 or other means is called latent. All bodies possess 
 latent heat, however cold they may seem to be. 
 
 Sources of Heat. The chief source of heat is 
 thought to be the earth itself, which many geologists 
 suppose to be a globe of burning matter. If we 
 descend far below the surface, as in mining, or even 
 well-sinking, we experience an increase in the tem- 
 perature : it is warmer. 
 
 If, as some believe, the temperature increases at the 
 rate of one degree for every fifty feet of descent, it is 
 certain that the interior must be in a fused or melted 
 state, the cool parts of which are the comparatively 
 thin crust of the earth, and which is occasionally 
 broken through by the combustible matter, or ac- 
 cumulated gases below, as in the case of earthquakes 
 or volcanoes. 
 
 Caloric. Another source of heat is the sun, but 
 heat, or caloric, as it is called in science, may be 
 developed from almost everything. As we have seen
 
 128 OUTLINES OF SCIENCE. 
 
 in chemistry, heat is produced by chemical action in 
 the mixing of some cold, liquids, as water and sulphuric 
 acid, or a liquid and solid, as water and quicklime. 
 
 Friction. Caloric is also produced by the friction 
 of solids. The Indian will procure fire by rubbing 
 pieces of wood together ; the school-boy heats a button 
 by rubbing it on wood ; so great a heat is caused in 
 boring cannon, that a continuous supply of oil or 
 water is required to prevent the metal from softening. 
 For a similar reason oil or some other fatty substance 
 is required to be applied to the wheels of railway or 
 other carriages, to prevent them from taking fire 
 through the excessive heat which rapid motion would 
 cause. The friction of fluids, such as oil and water, 
 does not produce heat. 
 
 Conduction of Heat. Some bodies conduct heat 
 better than others ; iron and other metals better than 
 wood or glass ; a piece of burning wood, or red-hot 
 glass may be held much nearer the heated part than 
 a similar heated rod of metal could be. For this 
 reason the handles of tea and coffee pots should be 
 made not of metal, but of wood, ivory, or some other 
 bad conductor. 
 
 If a sheet of paper be wrapped tightly round a 
 metal rod, and held in the flame of a spirit lamp, the 
 paper will not take fire, because the metal carries the 
 heat away so rapidly. If a wooden rod be used instead 
 of metal, the paper will soon take fire. 
 
 Dress. By wrapping ourselves in various kinds of 
 clothing, we keep the caloric from passing out of our 
 bodies, and thereby we are kept warm. By a series 
 of experiments it has been shewn that a thermometer 
 which was cooled in the air in 27 seconds, required 
 more than 1000 seconds to cool when wrapped in 
 cotton wool, while other material required a longer 
 time, increasing as follows : sheep's wool, raw silk,
 
 HEAT. 129 
 
 beaver's fur, eiderdown, and hare's fur, the last of 
 which caused the time of cooling to be 1315 seconds. 
 
 Roofs. Thatched cottages are warmer in winter, 
 and cooler in summer than those covered with tile or 
 slate. In winter the warmth is not conducted outwards 
 so quickly, and in summer the heat is not so quickly 
 conducted within, as straw is not so good a conductor 
 as slate and tile. For a similar reason, snow on the 
 ground keeps the soil warm. 
 
 Heat Ascends. We place water above a fire to heat 
 it ; the lower portion becomes warm and ascends, 
 while the cooler descends and takes its place, until 
 all becomes similarly heated, and when the heat has 
 accumulated to 212 Fahrenheit, the liquid boils. 
 There are continuous currents all the time the water is 
 being heated. 
 
 The same phenomenon takes place when air is 
 heated. That which is over the equator is greatly 
 rarefied, and rises, cooler air rushes in to supply its 
 place, and thus winds more or less powerful are 
 caused. 
 
 Ventilation. The ascent of the heated air enables 
 us to ventilate buildings, ships, mines, &c. A mine 
 is ventilated by keeping up a great fire at the bottom 
 of it ; the heated air ascends, and other cold air 
 rushes down the mine to supply its place. 
 
 Buildings have openings of various kinds in the 
 roof to let out the heated air, but the whole subject 
 requires to be better understood by those who build 
 houses and ships. 
 
 In steamships the lower part of the vessel is kept 
 ventilated by the draught of the boiler furnaces. 
 
 QUESTIONS ON CHAPTER XXXVIII* 
 
 How is heat defined ? 
 
 Distinguish between sensible and latent heat.
 
 130 OUTLINES OF SCIENCE. 
 
 What is said about mine-sinking ? 
 
 What are the chief sources of heat? 
 
 What is the scientific name for heat ? 
 
 How is heat produced by chemical means ? 
 
 What examples are given of friction ? 
 
 Which are the best conductors of heat ? 
 
 How is wood shown to be a bad conductor ? 
 
 What is the chief advantage of dress ? 
 
 What is said of thatched cottages and of snow ? 
 
 What happens when water or air is heated ? 
 
 How is water heated ? What is boiling heatP 
 
 What enables us to ventilate ships ? 
 
 How 13 a mine ventilated ? 
 
 Why is a steam-vessel better ventilated P 
 
 CHAPTER XXXIX. 
 
 SEAT continue^. 
 
 Radiation. Caloric passes from a heated body in 
 straight lines, and in all directions, as does light 
 this is called radiation. Dark and rough surfaces 
 radiate heat, and also absorb it most quickly and per- 
 fectly. Whatever is required to retain heat, such as 
 teapots, boilers, &c., should be as light coloured and 
 as smooth as possible. 
 
 Absorption of heat takes place generally when it 
 passes through any substance. The darker the colour 
 of the substance, the greater is the amount of heat 
 absorbed. 
 
 Reflection. Heat is readily reflected by plates of 
 polished metal, but there is a great difference in their 
 reflecting power. A plate or reflector of polished gold 
 will reflect much more than a plate of brass, and more 
 than twenty times the amount of heat that a blackened 
 metal plate will reflect. The angles of incidence and 
 reflection are equal, as in the case of the reflection of 
 light.
 
 HEAT. 131 
 
 Expansion and Contraction. All bodies, whether 
 solid, gaseous, or fluid, are expanded by heat. There 
 are two or three apparent exceptions, to be hereafter 
 noticed. 
 
 If a piece of iron which exactly fits a ring when 
 cold, be made hot, it will not go into the ring until it 
 becomes cold again. Clocks and watches, which are 
 not specially adapted for a variable climate, are liable 
 to gain or lose according as the weather becomes cold 
 or hot ; hence in warm weather we find it necessary 
 to shorten the pendulum, and in cold weather to 
 lengthen it in the same proportion. Cast-iron pipes 
 are lengthened about six inches in 300 yards by the 
 change from winter to summer. 
 
 Now that so much iron work is used in buildings, 
 it is of the utmost importance that this should be 
 allowed for, and it is so in the Menai, and other large 
 bridges, as well as in other structures which are super- 
 intended by really scientific engineers. 
 
 Iron tires are applied to wheels when very hot, so 
 that as they become cold they contract, and grip the 
 parts of the wheel more closely. 
 
 Contraction Applied. It happens occasionally that 
 the walls of a building get out of the perpendicular, 
 so as to become unsafe. This was the case with a 
 large museum gallery in Paris, and to restore the 
 inclined wall to its upright position, bars of iron were 
 passed from side to side, and screwed tightly by nuts 
 on the outside. After screwing them to the utmost 
 while cold, the bars were heated, and while expanded, 
 the nuts were screwed up more tightly than before. 
 The result was, that as the heated bars became cold, 
 they contracted again, and by a silent but irresistible 
 force drew the wall upright. 
 
 Sudden Expansion. If a quantity of sulphuric acid 
 be carelessly poured into a glass vessel of cold water,
 
 132 OUTLINES OF SCIENCE. 
 
 the heat generated will break the vessel, especially if 
 the glass be thick. Hot water will often have the 
 same effect, and glass may be broken by running a 
 red-hot wire over a plate of it, when it may be as 
 easily cracked off as though it had been starred with a 
 diamond. 
 
 The reason is that the inner surface expands much 
 more rapidly than the outer, and is torn from the 
 outer by the sudden expansion. 
 
 Ice and Clay. Water does not continue to con- 
 tract by cold below the temperature of 40 Fahrenheit. 
 Below 40 as the cold increases, it expands, so that 
 when it becomes ice, its specific gravity is less than 
 that of water, and it rises to the surface and floats. 
 
 Design. By this wise and beneficent arrangement, 
 rivers are prevented being permanently frozen ; were 
 it otherwise, the whole of the water would become a 
 mass of ice, and the living creatures in it would perish. 
 
 The wonderful expansive force of small quantities 
 of water may be seen by the breaking off of rocks 
 which have been bored, and water poured into the 
 hole during a frost. The moisture absorbed by earthy 
 matter in the autumn, frequently causes landslips 
 during the ensuing frosts. 
 
 An unpleasant illustration of expansive force is 
 seen in the bursting of our water bottles and jugs by 
 a severe frost. At such times they should be emptied 
 when the frost begins. 
 
 Clay, which is commonly spoken of as an exception 
 to the rule as to expansion by heat, takes up less 
 space after it has been baked, but the reason doubtless 
 is that it parts with much of its water in the process 
 of baking, and therefore becomes substantially less. 
 Clay, like other earths, is broken up, and its particles 
 loosened, by the effect of frost. 
 
 The expansiveness of metals is generally in accord- 
 ance with their fusibility. Those which are easily 
 fusible, such as lead, are also very expansive.
 
 HEAT. 133 
 
 QUESTIONS ON CHAPTEE XXXIX. 
 
 What is radiation ? 
 
 What colours and surfaces radiate most quickly ? 
 
 What occurs when heat passes through a substance? 
 
 What metal has the greatest reflecting power? 
 
 How are all bodies afiected by heat or cold ? 
 
 Give examples of expansion by heat. 
 
 How do expansion and contraction affect buildings ? 
 
 In what condition are the tires put on wheels ? 
 
 What remarkable case of contraction is mentioned ? 
 
 What occurs when sulphuric acid and water are mixed ? 
 
 Give some reason for the breaking. 
 
 What occurs to water below 40 Fahrenheit ? 
 
 What would happen if it kept on contracting ? 
 
 How are rocks sometimes split ? 
 
 Name another exception to the rule. 
 
 What is said of the fusibility of metals ? 
 
 CHAPTER XL. 
 
 HEAT continued. 
 
 Thermometer (from thermos, heat, and metron, a 
 measure) is an instrument for measuring the degrees 
 of heat in the atmosphere by expansion, the invention 
 of which has been ascribed to various persons. 
 
 The ordinary thermometer consists of a glass bulb, 
 having a fine stem ; the bulb and stem are filled to a 
 certain height with alcohol or mercury, and in the 
 rest of the tube there is a vacuum. 
 
 By subjecting the mercury in the tube to a great 
 heat, it expands, and fills up the small tube, when it 
 is carefully sealed np, and allowed to cool. It is then 
 graduated, so that we may reckon the degrees of heat 
 or cold. When plunged into boiling Water for a short 
 time, the water rises to boiling point, 212 Fahrenheit. 
 If placed in snow or melted ice, it falls to 32. 
 
 12
 
 134 OUTLINES OF SCIENCE. 
 
 The Centigrade and Reaumur Thermometers. The 
 thermometer used in France is called Centigrade. Its 
 freezing point is marked 0, while its boiling point is 
 100. 
 
 That used in Germany is called Reaumur, which 
 also has its freezing point 0, and its boiling point is 
 only 80. The centigrade is the one most in use on 
 the continent of Europe. 
 
 Evaporation. Most fluids, and many solids, con- 
 stantly give off vapour. When this is done without 
 disturbing the surface, it is called Evaporation. When 
 the surface is disturbed it is called Ebullition or boil- 
 ing. Heat is the cause of both. 
 
 Evaporation produces cold, hence in India, and 
 other hot climates, water is poured or sprinkled freely 
 on floors, furniture, roofs, tents, &c., because its evapo- 
 ration lessens the heat. 
 
 Various liquids, such as prussic acid, will freeze by 
 evaporation. Thus if ether be poured upon water, 
 and placed under the receiver of an air-pump, when 
 the air is exhausted the ether will boil away, the heat 
 will be evaporated, and the water will freeze. 
 
 The Hygrometer. This is an instrument, various in 
 form, made to measure the quantity of water in the 
 atmosphere. As all vegetable fabric absorbs moisture, 
 it thickens and shortens in the process, and is some- 
 times used as a hygrometer. 
 
 The ropes in a drying-ground may be tightened by 
 wetting them, and on one occasion, while raising the 
 famous Egyptian Obelisk in front of St. Peter's, at 
 Rome, this fact was usefully illustrated. When it 
 was found that the ropes were a little too long, so 
 that the work could not be completed, some one in the 
 crowd shouted out, " Wet the ropes." This was done, 
 and the result was that the ropes contracted so much, 
 as to raise the obelisk to its vertical position.
 
 HEAT. 135 
 
 Dew. Part of the moisture which is evaporated 
 from the surface of the earth during the day, is de- 
 posited there again during the night in the form of 
 dew. Vegetable fibre, and similar substances which 
 radiate heat rapidly, are the first recipients of the 
 dew, consequently the leaves of trees, grasses, &c, are 
 frequently refreshed by it. 
 
 Kadiation and dew-deposit are both more rapid 
 when the sky is clear ; in cloudy weather the vapour 
 is driven back to the earth. 
 
 Rain. When the moisture which has been evapo- 
 rated rises into colder regions, it becomes dense and 
 forms clouds. 
 
 If the air be disturbed by electricity or other causes, 
 the vapour forms into round drops and becomes too 
 heavy to float. It then falls in the form of rain. 
 
 Snow and Hail. Sometimes, as these drops fall, 
 they pass through a very cold current of air, and are 
 frozen into little lumps of ice as hail, or into less solid 
 masses as snow. 
 
 Freezing Mixtures. If salt and snow be mixed 
 together, the snow will be melted, and a thermometer 
 placed in the fluid will fall to zero. Solid carbonic 
 acid and sulphuric ether, when mixed, form the coldest 
 known substance. 
 
 A mixture of crystallized chloride of calcium 
 with snow produces the coldest known temperature. 
 The mercury of a thermometer placed in it, will sink 
 to 66 below zero. 
 
 Other freezing mixtures are snow and diluted nitric 
 acid, or snow and potash, which are easily obtained. 
 The solid carbonic acid can only be obtained from 
 carbonic acid by a pressure of thirty atmospheres, 
 450 Ibs. to the square inch, which reduces it to a 
 liquid, and that liquid becomes a solid at 94 below 
 zero. 
 
 122
 
 136 OUTLINES OF SCIENCE". 
 
 QUESTIONS ON CHAPTER XL. 
 
 How can we measure degrees of heat ? 
 
 Describe the thermometer. 
 
 What thermometer is used in France? 
 
 What is the difference between the Centigrade and Beaumur r 
 
 What is evaporation ? What ebullition ? 
 
 How is heat lessened in hot countries ? 
 
 What effect has evaporation on ether ? 
 
 What is the use of the hygrometer ? 
 
 How is vegetable fibre affected by moisture ? 
 
 Give some examples of rope-shrinking. 
 
 What is dew ? When is it most heavy ? 
 
 What articles are most benefited by it ? 
 
 How is dew affected by cloudy weather ? 
 
 Explain how rain is formed. 
 
 What is hail, and how formed ? 
 
 What articles form the coldest substance ? 
 
 What mixture sends the mercury down to 66 below zero ? 
 
 How is solid carbonic acid obtained ? 
 
 What is its temperature?
 
 PHYSIOLOGY OF MAX. 137 
 
 PHYSIOLOGY OP MAN. 
 
 CHAPTER XLI. 
 
 THE bodily constitution of man is one of the most 
 important to all, but one of the least understood by 
 the majority of persons. The health of the mind 
 depends largely upon that of the body, while the 
 latter is under our control to a much greater extent 
 than is generally understood. 
 
 Man can never be cheerful and happy, as a rule, 
 except when in health. This applies especially to 
 young persons, whose mental faculties are quickly in- 
 fluenced by the disorder of the body. 
 
 Suitable food, exercise, and cleanliness, pure water, 
 and good air, are essential to perfect health and 
 vigour. 
 
 Waste of the Body. It has been proved by experi- 
 ment that man cannot take exercise, or use any bodily 
 force, without some waste of the material of which 
 the body is composed. It is quite possible indeed to 
 /ose some of its particles in a state of absolute quiefc 
 or idleness, for what is called the insensible perspira- 
 tion would still go on. 
 
 The chief process by which this waste is repaired, 
 is by taking wholesome food ; it is not the only 
 means, because, as we have said above, pure air is 
 required to assist in this process. 
 
 123
 
 1S8 OUTLINES OF SCIENCE. 
 
 Waste Repaired. Man must therefore eat to live, 
 and it is well that young people should understand 
 how the digestion and assimilation of the food is ac- 
 complished, what delicate machinery is in operation to 
 keep them in life and health, and how wisely and 
 beautifully all has been designed by the Creator for 
 the happiness of his creatures. 
 
 A tolerably accurate knowledge of the bodily for- 
 mation and functions will go far to prevent the blun- 
 ders and excesses to which young people are especially 
 liable. 
 
 The Bodily Frame. The great internal supporter 
 of the body is the bony skeleton, which contains more 
 than two hundred bones. The largest of these are 
 the vertebrae of the backbone, which in early life con- 
 tains thirty-three separate bones, some of the lower of 
 which, however, unite as we grow old. 
 
 The Spinal Marrow. The backbone contains the 
 spinal marrow in a hollow groove in its centre, and at 
 the top of the vertebrae the skull, formed of numerous 
 separate bones, some of which unite as we come to 
 manhood, and which contains the brain. 
 
 From the marrow and brain the nervous system 
 extends all over the body like the numerous branches 
 of a spreading tree, and wherever pain can be caused 
 there is a nerve. 
 
 The Ribs. Connected with the vertebral column or 
 backbone are the ribs, twelve on each side, eighteen 
 of which are usually attached to the sternum or 
 breastbone, and within which the most important 
 soft parts of the human frame are contained and pro- 
 tected from injury, such as the heart, lungs, and other 
 vital organs. 
 
 The Limbs and Synovia. The legs are joined to 
 the pelvis, which conies between them and the back- 
 bone. Each leg is composed of thirty bones, and
 
 PHYSIOLOGY OF MAN. 139 
 
 eacli ami has the same number, and these are fastened 
 together very strongly by a tough substance called 
 ligament or cartilage, and where one bone plays or 
 moves inside another, as in the joints, the ends which 
 come in contact with each other are not only lined 
 with a soft smooth cartilage, but within each socket an 
 oily fluid is secreted or formed, called the synovia. 
 
 This acts on the joints like oil on the wheels of 
 the steam engine. When by accident or other means 
 this joint-oil has been interfered with or allowed to 
 escape, the result is always a stiffness of the limb. 
 
 The Mnscles. A mere skeleton would not be able 
 to maintain the upright position, although the feet of 
 man are admirably formed for that purpose. A series 
 of strong bands of flesh called muscles are necessary, 
 whith under the influence of the will contract or 
 shorten, and pull the various parts of the body in dif- 
 ferent directions. 
 
 The chief of these are the muscles of the spine, 
 which keep the body from falling forward, the muscles 
 of the thigh, and those of the legs. These are lapped 
 over each other so regularly, that an anatomist can 
 separate one from the other, and each has its proper 
 name and office. 
 
 The Skin. Over the muscles we find the skin, 
 which is much more complex than it appears to be 
 from the outside. It consists of two parts, the dermis 
 and the epidermis the dermis lies immediately over 
 the muscles, and is very sensitive of pain or injury ; 
 the epidermis, or outer skin, does not feel pain, so 
 that you may remove a portion of it without suffering. 
 
 The epidermis, or cuticle, does not absorb anything 
 easily, otherwise we should be always in danger of 
 blood poison ; but now we can handle poisons and 
 even putrid matter without danger, so long as the 
 skin remains whole.
 
 HO OUTLINES OF SCIENCE. 
 
 Blood Poison. It is quite otherwise with the der- 
 mis, which is so easily poisoned or inflamed, that 
 anatomists, in operating on dead bodies, have some- 
 times died from an accidental cut or scratch made by 
 their own dissecting knives. 
 
 Vaccination. So in vaccination or inoculation the 
 virus is introduced into the blood-vessels of the der- 
 mis, after cutting through the cuticle. 
 
 The skin performs an important function or duty, 
 as it is proved that an acid called urea, as well as car- 
 bonic acid and watery vapour, are filtered outwards 
 through the million of pores which are spread over it 
 like the meshes of a net, and through which it is 
 computed that about eighteen ounces of water, and 
 nearly an ounce each of carbonic acid and solid matter 
 passes every day. 
 
 Men who are employed at gas works, or on board 
 large steamers, afford examples of the loss of material 
 through the skin. Such men, who have been weighed 
 on going to work, have been found to lose from four 
 to five pounds weight in the course of as many hours. 
 
 Between the cuticle and the true skin there is a 
 layer of colouring matter, which in the negro race is 
 black, and varies according to the complexion of the 
 various races. 
 
 QUESTIONS ON CHAPTER XLI. 
 
 Why 13 the study of physiology important ? 
 
 What is the result of every bodily movement ? 
 
 How is the waste repaired ? 
 
 What is the great supporter of the body ? 
 
 How many form the backbone ? 
 
 What does the backbone contain ? 
 
 How many in each arm and leg ? 
 
 To what is the nervous system compared ? 
 
 In what are the heart and lungs enclosed ? 
 
 How many ribs are there in each side ? 
 
 What is the synovia ? WLat is ligament t
 
 PHYSIOLOGY OF MAN. 141 
 
 What is the function or duty of the muscles ? 
 What are the dermis and epidermis ? 
 Show how the epidermis is fitted for its duty ? 
 What is the special duty of the skin ? 
 What is ibund between the two skins ? 
 
 CHAPTEE XLII. 
 
 THE DIGESTIVE PROCESS. 
 
 Food, and the Mouth. Suitable food being pro- 
 vided, it must be well masticated or chewed, during 
 which it is mixed with a fluid called the saliva, or 
 spittle, which is secreted in the mouth, by six little 
 glands. This saliva acts chemically on some kinds 
 of food ; it will change the starchy elements of the 
 food, which are not nutritious, into sugar, which is 
 highly so. It moreover prepares the food for easier 
 digestion in the stomach, and therefore thorough mas- 
 tication is important. 
 
 The Teeth. The teeth, which perform so useful a 
 purpose, are thirty-two in number, of three different 
 forms, and adapted to all kinds of food. They are 
 faced with a hard enamel, and as the back of the 
 tooth is softer than this enamel, the tooth wears down 
 with use, and always maintains a sharp edge, and this 
 especially in the incisors, or cutting teeth. 
 
 When the food has been thus masticated and insali- 
 vated, it is ready to be swallowed, and passes over the 
 tongue into the gullet or esophagus, down which it 
 goes into the stomach. 
 
 The Stomach and its Duties. When the food 
 passes down the gullet into the stomach, that organ 
 contracts and moves it about, thus mixing it with a 
 fluid which is secreted by numerous glands in its coats, ; 
 and which is called the gastric juice.
 
 142 OUTLINES OF SCIENCE. 
 
 The acid or dissolving power of this fluid is very 
 great, and it speedily reduces the solid food to a pulp, 
 after which it is allowed to pass through the pylorus 
 into the duodenum or large bowel, in the state of 
 chyme. Part of the liquid mass is believed to be^ 
 absorbed through the sides of the stomach, and 
 carried direct into the bloodvessels which are scattered 
 over it. The pylorus is the lower opening of the 
 stomach. 
 
 Time of Digestion. By a singular circumstance, 
 Dr. Beaumont of America was enabled to make ex- 
 periments of the time in which various kinds of food 
 would be digested. A young Canadian, named Alexis 
 St. Martin, had received a gunshot wound in the 
 stomach ; the wound healed round the edges, without 
 closing, and left a hole, through which the contents of 
 the stomach could be seen. 
 
 Shortly afterwards a natural valve was formed over 
 the inside of this hole, which could be pushed in- 
 wards, but which would not allow the contents of the 
 stomach to escape. 
 
 Experiments. Dr. Beaumont hired him for the 
 sake of performing experiments, and the result of 
 frequent trials proved that various kinds of food were 
 digested in about the following spaces of time : 
 
 Fibrinous food, such as roast beef and mutton, in 3 
 hours ; salt pork, 4J hours ; strong beef soup, 5 hours. 
 
 Albuminous food. Eggs, raw, 1 hour soft boiled, 
 3 hours ; hard boiled, 5 hours ; boiled fish, 2 hours ; 
 fried fish, 3 hours ; raw oysters, 2 to 3 hours. 
 
 Gelatinous food. Tripe, 1 hour; boiled real, 4 
 hours ; roast chicken and sucking pig, 2 to 3 hours. 
 
 Fatty food. Broiled fat pork, 3 to 4 hours ; fried 
 bacon, 5 hours. 
 
 Cheese-like food. Boiled milk, 2 hours ; raw milk,
 
 PHYSIOLOGY OF MAN. 143 
 
 nearly 3 hours ; toasted cheese, 3 hours ; raw cheese, 
 4 hours. 
 
 Farinaceous food. Boiled rice, 1 hour; boiled 
 potatoes or beans, 2 hours ; baked wheaten bread, 
 3 to 4 hours. 
 
 Mucilaginous food. Boiled carrots, parsnips, or 
 turnips, 3 hours. ^ 
 
 It must be noticed that when the stomach is over- 
 laden with a heavy meal, the process of digestion is 
 slower, because the gastric fluid cannot so easily mix 
 with all the particles, to reduce them to chyme. An 
 ordinary meal of mixed food is so reduced in about 4 
 hours. 
 
 Chyme changed to Chyle. When the food in the 
 state of chyme passes into the duodenum, which is 
 the part of the intestinal canal next to the stomach, 
 it receives two other additions, the bile from the gall- 
 bladder, and a secretion from the pancreas or sweet- 
 bread, which lies behind the stomach. 
 
 The Bile. The alkali of the bile neutralizes the 
 acid of the chyme, the starch in the food is converted 
 into sugar, and the whole nature of the fluid is 
 changed. It is now called chyle, and is in a condition 
 to be assimilated, or used to repair the bodily waste 
 of which we have spoken above. 
 
 Assimilation. The chyle is forced along the small 
 intestines, which succeed the duodenum, by what is 
 called a peristaltic, or worm-like motion, and in its 
 passage the nutritious portions of the chyle are imbibed 
 or absorbed by minute spongioles, in the inside of the 
 bowels. 
 
 The Mesentery. These are connected with the 
 mesenteric gland, and passing along, meet at one 
 point, and are received in a tube about the size of a 
 little finger, and which is called the thoracic duct.
 
 144 OUTLINES OF SCIENCE. 
 
 Nutrition. This thoracic duct passes upward to the 
 top of the aorta, one of the chief blood vessels to be 
 noticed presently, and empties itself into the large 
 vein called the vena portse, whence it becomes mixed 
 with the blood, and is used for all the purposes of 
 nutrition, renovation, growth, and repair of waste. 
 By this time the chyle has assumed a pinkish colour, 
 and if kept still will separate, like blood, into a solid 
 and a watery part. 
 
 Epithelium. The whole interior of the alimentary 
 canal, from the lips downward, is lined with a soft 
 coating called the mucous membrane, also the epithe- 
 lium, very tender and sensitive, and which is full of 
 glands of various kinds, for the objects just mentioned. 
 
 QUESTIONS ON CHAPTEE XLII. 
 
 What is mastication ? Why important ? 
 
 How does the saliva affect the food ? 
 
 With how many teeth are we supplied ? Describe them. 
 
 Whither does the food pass after mastication ? 
 
 What happens to it in the stomach ? 
 
 Into what is it changed by the gastric juice ? 
 
 What is the pylorus ? And the duodenum ? 
 
 What becomes of a portion of food in the stomach P 
 
 How have we learned some facts about digestion ? 
 
 How long does fibrinous food take to digest ? 
 
 What is gelatinous food ? How long does that require P 
 
 Name the foods which are most easily digested. 
 
 What is added to the chyme in the duodenum? 
 
 What effect has the bile on the food ? 
 
 Show how the nutritious food is assimilated. 
 
 What are the duties of the mesentery and thoracic duct P 
 
 How la the alimentary canal lined ?
 
 PHYSIOLOGY OF MAN. 145 
 
 CHAPTER XLIII. 
 
 THE BLOOD AND ITS VESSELS. 
 
 Its Composition. The blood is said by chemists to 
 be "an alkaline fluid, consisting of water, and of 
 solid and gaseous matter." 
 
 In its healthy state it is always at a temperature 
 of about 100 of Fahrenheit, marked blood heat on 
 the thermometer. 
 
 In every 100 parts of blood there are 79 parts of 
 water, and 21 parts of dry solids, just as in air there 
 are about 79 parts of nitrogen, and 21 of oxygen. 
 
 The globules of blood in human beings are always 
 circular, while in other animals they are elliptical or 
 oblong in form. 
 
 Separation. When blood is drawn from a body, it 
 quickly cools, and in about fifteen minutes it separates 
 into two different constituent parts a clear yellowish 
 liquid called the serum, and a much thicker and red 
 part called the dot or crassamentum. 
 
 The clot contains the more solid portions, called 
 fibrin, from which the skin, muscles, and vessels are 
 made, and which usually sinks to the bottom as the 
 blood cools. It also contains iron, and various 
 phosphates. 
 
 Haematine. The red colour of living blood is 
 caused by the presence of millions of red corpuscles or 
 globules, of the shape of a flattened pea, and of which 
 many thousands could lie on a square inch. Small 
 as they are, they have a little ball of white matter 
 inside, as the red matter or hsematine is only a colour- 
 ing case or envelope, and can be washed away. 
 
 The serum contains more fluid matter, and albu- 
 men. The whole constituents of the blood (26 in 
 number) are water, heematine, albumen, fibrin, fatty 
 
 13
 
 146 
 
 OUTLINES OF SCIENCE. 
 
 matter, iron, and very minute portions of various 
 other chemical substances. 
 
 Lymph. There is another fluid found in the various 
 cavities of the body which is not coloured like the 
 blood, but which contains fibrin, and is daily poured 
 into the blood. This is called lymph, its vessels are 
 called lymphatics, and so far as is known at present, 
 it exudes through the tissues as the chyle is being as- 
 similated in the process of digestion. 
 
 The Circulation. Since there is a continual waste 
 going on in the human frame, which can only be re- 
 paired as new material is supplied by the blood, it is 
 necessary that there should be a machinery to carry 
 that fluid to all parts of the body. Such a machinery 
 was discovered to exist by Dr. Harvey, who lived in 
 the reign of James I. 
 
 By this discovery he learned that blood is sent 
 from the heart through a system of arteries, and that 
 it returns to the heart through a similarly arranged 
 system of veins. 
 
 The Heart. The heart is the great reservoir of the 
 
 blood ; it is ar- 
 ranged in four 
 separate cham- 
 bers or com- 
 partments with 
 very strong 
 muscular walls 
 between, and 
 containing ele- 
 ven valves, 
 which only 
 open one way, 
 so that blood 
 
 Fig. 25. which has once 
 
 passed through them, can never return the same way.
 
 PHYSIOLOGY OF MAN. 147 
 
 From fig. 25, which is a front view of the heart, with 
 an outline of the lungs, and the pulmonary or lung 
 veins and arteries, it will be seen that there is an 
 intimate connection between the heart and lungs. 
 
 Circulation. By the muscular action of the heart, 
 the venous blood, of a dark red colour, is forced 
 through the right ventricle into the large pulmonary 
 arteries, d d. By this it is spread through numerous 
 branches over the surface of the lungs and air pas- 
 sages, and passing through exceedingly minute chan- 
 nels, called capillaries, it returns by the pulmonary 
 veins through four valves, 'into a third chamber of the 
 heart, called the left auricle. From the left auricle 
 it passes by another valve into the left ventricle, a 
 chamber with very strong muscular walls, from which 
 it is pumped out of the aorta, k, through numerous 
 arteries, to every part of the body. 
 
 Altered State of the Blood. As the blood returns 
 through the pulmonary veins to the heart, it is seen 
 to be of a lighter colour than when it was sent out, 
 so that it must have undergone an important change 
 in the course of its passage through the lungs. This 
 brighter coloured blood is sent through the arteries all 
 over the body, and passing through capillaries at their 
 extreme ends, comes back by the veins to the heart of 
 a much darker colour. In its course it supplies ma- 
 terials for growth and renovation to all parts of the 
 body, and evidently takes from the interior some 01 
 its impure or waste matter, which is brought back to 
 be purified in the lungs. 
 
 Venous and Arterial Blood. The cause of this 
 change of colour is not thoroughly understood, but it 
 is believed to be due to the presence of oxygen or car 
 bon. When pure air is taken into the lungs, it comvs 
 into contact with the venous blood in the pulmonary 
 arteries, which contains much carbonic acid. The
 
 148 OUTLINES OF SCIENCE. 
 
 oxygen is taken into the blood through the very thin 
 membrane of which the lung passages are composed, 
 and the carbonic acid passes through into the passages 
 to be expired or breathed out of the mouth. By this 
 process of inhaling pure air, the venous blood becomes 
 arterial. 
 
 On this account it is that pure air is so important 
 to health, for without it the same air has to be breathed 
 over again, and in a short time all the pure oxygen 
 will be exhausted. 
 
 Carbonic Acid formed. The air is taken into the 
 lungs dry and pure ; it is exhaled again moist and 
 abounding in carbonic acid. If any person breathe 
 through a glass tube into a tumbler of pure lime-water, 
 it becomes turbid or thick, thereby proving that car- 
 bonic acid gas has been forced into it. It is this 
 carbonic acid which forms a chief ingredient in the life 
 and nourishment of plants. They take in carbonic 
 acid and expel oxygen. Animals use the oxygen, 
 and expel the carbonic acid. 
 
 QUESTIONS ON CHAPTER XLIII. 
 
 How is the blood defined by chemists ? 
 
 Of what is it composed ? Its temperature ? 
 
 Of what shape are the globules in human blood? 
 
 What happens when drawn blood cools ? 
 
 What is contained by the clot ?. 
 
 What is hsematine ? Of what is serum composed ? 
 
 What is meant by lymph and lymphatics ? 
 
 How is it supposed to enter the blood ? 
 
 How is the waste of the body supplied ? 
 
 Who discovered the circulation of the blood ? 
 
 What are the arteries ? and the veins ? 
 
 How is the heart divided ? How many valves ? 
 
 With what, other organ is the heart connected ? 
 
 Describe the action of the heart and lungs. 
 
 What change takes place in the lungs ? 
 
 How is arterial blood known from venous ? 
 
 What is supposed to change the colour ? 
 
 Why is pure air of great importance ? 
 
 What is remarkable in the feeding of plants ?
 
 PHYSIOLOGY OF MAN. 149 
 
 CHAPTEE XLIV. 
 
 ARTERIES, VEINS, CAPILLARIES, AND SECRETIONS. 
 
 THE arteries are always found empty of blood after 
 death. They consist of three coats, the outer of 
 which is very elastic, the middle less so, and the inner- 
 most least so of all. 
 
 The result of this is that in the case of the severance 
 of an artery by any violent means, the inner coat of the 
 artery is first to break, and curling up, draws the 
 whole end of the artery into the tube, like a plug, 
 which thus prevents the rapid escape of blood. 
 
 The arteries are nearly straight, and always well 
 protected by bones and muscles. The veins are 
 similar in structure, but more branched and crooked ; 
 the blood flows through them with less force, so that 
 the wound of a vein is not so dangerous as that of an 
 artery, nor so difficult to cure. 
 
 The Capillaries. These are so small, that the pas- 
 sage of blood from the arteries to the veins cannot be 
 seen by the naked eye. 
 
 The Pericardium. The heart is surrounded by a 
 bag called the pericardium, which contains a fluid, 
 and the whole of the lungs, heart, &c., are contained 
 in and protected by the bony cavity of the chest, and 
 a strong membrane that lies below them, called the 
 diaphragm. 
 
 Secretions. The most important of these are the 
 saliva, the gastric juice, the bile, the pancreatic fluid, 
 lymph of various kinds, that of perspiration, and the 
 urine. Like the action of the heart and other impor- 
 tant organs, these secretions are carried on quite 
 independent of the will, for example, the sight of 
 fruit, or other palatable things, or even the thought of
 
 150 OUTLINES OF SCIENCE. 
 
 them, will sometimes cause the mouth to water, that 
 is, cause the saliva to flow. 
 
 Secretion is that process by which materials are 
 separated from the blood, and from the organs in 
 which they are formed. They are either made use of 
 in the body, or expelled from it as useless. 
 
 Secretion is as necessary to health as nutrition, and 
 may be arranged in three divisions, ^ exhalations, 
 when moisture is breathed out from the mucous mem- 
 brane, follicular secretions, and glandular secretions. 
 
 Where material is discharged from the body, as in 
 the case of perspiration, it is called an excretion. The 
 skin is furnished with numerous small holes or pores, 
 which are the openings of small hollow organs called 
 follicles, with membranous sides. These organs are 
 usually filled with fatty or albuminous matter. 
 
 Perspiration. This is a follicular secretion of a 
 watery vapour, which is incessantly passing off through 
 these pores. It consists chiefly of water, but contains 
 also acetic acid, muriates of soda and potash, and 
 other solids. 
 
 The free flow of this secretion is essential to health, 
 for whenever the pores of the skin are closed, disease 
 of some kind immediately ensues. Hence cleanliness 
 and exercise are very important, as tending to promote 
 its free action. 
 
 Glands. Glandular secretions are of different sorts ; 
 the chief are the tears, saliva, bile, milk, pancreatic 
 fluid, and the urine. 
 
 Saliva. Of the saliva and its uses we have spoken 
 elsewhere, as being of great importance in changing 
 the starch of the food into sugar, and so rendering 
 easier the process of digestion. 
 
 Tears. These consist of the limpid fluid secreted 
 by what are called the lachrymal glands. The object 
 of tears is to moisten the cornea, and to prevent
 
 PHYSIOLOGY OF MAN. 151 
 
 friction, by flowing over the surface of the eyes. They 
 are also useful in washing off foreign substances from 
 the eyes. 
 
 Bile. This oily fluid is secreted by the liver; it is 
 of a yellowish-brown colour, and has a bitter taste. 
 The bile is separated from the blood by the liver, and 
 when not required for digestive purposes, it is stored 
 up in a hollow sac or bag, called the gall-bladder. 
 
 The use of the bile appears to be to change the 
 digestive food from chyme to chyle. It is also thought 
 to assist in causing the peristaltic or worm-like motion 
 of the bowels, as a deficiency of bile is usually accom- 
 panied by a torpid action of the bowels. 
 
 Pancreatic Juice. This fluid is secreted by an 
 organ which is common to all the vertebrate animals, 
 and which is known as the sweetbread. It is similar 
 to the salivary glands, but softer, and the liquid which 
 it secretes is like the saliva in appearance, and assists 
 in the process of digestion. 
 
 Urine. This is a fluid which is separated from the 
 blood by the action of the kidneys, to the extent of 
 thirty or forty ounces .per day, according to the 
 quantity of fluid drunk. Whenever the action of the 
 skin is deranged, the kidneys are affected ; when 
 perspiration ceases they are overworked, and often 
 become diseased in consequence. 
 
 It contains more than nine-tenths of water, with 
 some solid matters, chiefly urea, the basis of uric acid, 
 and some salts. 
 
 These secretions continue at all times, while we are 
 in health, even during our sleep, and are more or less 
 independent of our will. 
 
 From this bare outline of Physiology it will be seen 
 how needful it is that all should be clean in person 
 and habits, careful in the kind of food eaten, and in 
 the avoidance of exposure to draughts when heated.
 
 152 OUTLINES OF SCIENCE. 
 
 The illnesses of young persons are most frequently 
 caused by want of attention to the kind of food they 
 eat, and by needless exposure. 
 
 QUESTIONS ON" CHAPTER 2LIV. 
 
 In what state are the arteries after death? 
 
 Describe their construction, and the consequence of it. 
 
 How do the veins differ from the arteries ? 
 
 What is said of the capillaries ? 
 
 What is the pericardium, and what does it enclose ? 
 
 Name the principal secretions. 
 
 How is the saliva secreted ? What is its use ? 
 
 What is meant by excretion ? 
 
 By what means does the perspiration escape ? 
 
 Of what does the perspiration consist ? 
 
 What are said to promote this secretion ? 
 
 What are the chief glandular secretions ? 
 
 By what glands are tears secreted ? For what purpose ? 
 
 What is the chief use of the saliva ? 
 
 By what gland is the bile secreted ? 
 
 What are the properties and uses of the bile ? 
 
 What other fluid assists in digestion ? 
 
 What office is performed by the kidneys ? 
 
 Of what is the urine composed ? 
 
 By what other secretion are the kidneys affected P
 
 ZOOLOGY. 153 
 
 ZOOLOGY. 
 
 CHAPTER XLV. 
 
 ZOOLOGY, (from zoon, an animal, and logos, a discourse), 
 is a history of the animal kingdom, from man to the 
 lowest subject in the scale of animated creatures, 
 including every creature which is known to have life, 
 feeling, and motion. 
 
 The vast number of animals already known has 
 been classified by various naturalists, from Aristotle 
 downwards, and the classification has been rendered 
 most complete by Cuvier in his Animal Kingdom. 
 
 Classification. It has been found convenient in 
 natural history to arrange animals and plants, mine- 
 rals, &c., in divisions, classes, orders, genera, and 
 species, in accordance with certain features which are 
 similar in each, and by this means we are better able 
 to remember the various individuals. 
 
 All the animal kingdom is thus arranged in four 
 great divisions or sub-kingdoms, beginning from the 
 lowest grade, viz. : fiadiata, or rayed animals ; Mol- 
 lusca, or pulpy animals ; Articulata, or jointed animals ; 
 and Vertebrata, or backboned animals. 
 
 I. Radiata (from radius, a ray). This sub-kingdom 
 is divided into Jive classes, all of which are found in 
 water, and are very simple in structure. They are 
 called Infusoria, Zoophytes, Acalephse, Entozoa, and 
 Echiuodennata,
 
 154 OUTLINES OF SCIENCE. 
 
 Infusoria (from infusor, I pour in) consists of ani- 
 malcules, usually found in stagnant water, and so 
 small that they cannot be seen by the unassisted eye, 
 and their habits and formation can only be watched 
 by powerful magnifiers. They were called Infusoria, 
 because all liquids in Avhich either animal or vegetable 
 matter has been steeped or infused, quickly abound 
 with creatures of this class, of various and curious 
 shapes. 
 
 They are divided into two groups, one of which has 
 soft bodies, and the other is covered with a shell, 
 which, small as they are, help by their countless mil- 
 lions to swell the great mountains of the cretaceous 
 or chalky formation. 
 
 Zoophytes (from zoon, an animal, and phytos, a plant). 
 These are so called on account of their resemblance to 
 plants. They are very simple in construction, and 
 have this peculiarity, that if cut in two, each separate 
 piece becomes a perfect animal, so that from one 
 specimen many others may be obtained by such 
 divisions. 
 
 Examples : the sponge, hydra, coral insects, the 
 actinia, or sea-anemone, and others. 
 
 Acalephee (from acalepha, a nettle) are so called 
 because the creatures which compose the order have a 
 power of stinging in the fringe-like tentacula or arms 
 with which they are furnished. While living and in 
 the sea, they look like masses of clear jelly, with the 
 fringe beneath, but out of Avater they quickly lose their 
 power. Like the sea-anemone, the acalephse are 
 common on our coasts. 
 
 Entozoa (from entos, within, and zoon, an animal) 
 includes those creatures which live within and prey 
 upon the bodies of other animals. They are usually 
 known as intestinal worms, because one kind of them 
 is sure to be found in the intestines of animals, and
 
 ZOOLOGY. 155 
 
 curiously enough the species found in the ox family is 
 quite different from those found in the horse. 
 
 One of these, called the fluke, inhabits the liver of 
 sheep, while several kinds, among others the tape- 
 worm, infest the intestines of human beings. We 
 have no certain knowledge of the means by which 
 they are introduced into the bodies, but most likely 
 it is with raw or unripe food, or food that has become 
 partly decomposed. 
 
 Echinodermata, or spiny-skinned (from echinus, a 
 hedgehog, and dermus, the skin). This class includes 
 the various kinds of star-fish, sea-urchins, and other 
 rough or spiny-skinned rayed creatures. 
 
 These have a faculty, like the polypi, of reproducing 
 an arm or ray which has been broken off, and one, 
 the brittle star-fish, will throw off its arms when pur- 
 sued or alarmed. 
 
 The sea-urchin has numerous spines, which help it 
 to move from place to place on the ground. 
 
 These, in common with all others of the radiata, 
 have no heart, no circulation, and no distinction of sex. 
 
 QUESTIONS ON CHAPTER XLV. 
 
 "What is zoology ? Name some eminent naturalists. 
 
 What does the animal kingdom include ? 
 
 In how many great divisions is it arranged? 
 
 Give the meaning of mollnsca and vertebrata. 
 
 How are the radiata sub-divided ? 
 
 What are included in the infusoria ? 
 
 Why are zoophytes so called ? Some examples. 
 
 Name some peculiarities of the zoophytes. 
 
 Where are the acalephse found ? 
 
 What are the entozoa ? Why so called ? 
 
 What is said about the horse and the ox? 
 
 Where is the fluke found ? And the tape worm ? 
 
 What is meant by echinodermata ? 
 
 What creatures are included in it ? 
 
 What is peculiar to them ? 
 
 Of what are all the radiata deficient ? 
 
 Q-ive an example of each radiate order.
 
 156 OUTLINES OF SCIENCE. 
 
 CHAPTER XLVI. 
 
 SUB-KINGDOM MOLLUSCA. 
 
 Mollusca, or soft animals (from mollis, soft), are so 
 called because they have no jointed skeleton, nor any 
 connected nervous system, the nerves being spread 
 about in knots or ganglia, and the bodies soft like the 
 snail, oyster, cuttle-fish, nautilus, &c. 
 
 They may be conveniently arranged in three classes, 
 ACEPHALA, GASTEROPODA, and CEPHALOPODA. 
 
 The Acephala, or headless animals (from a, with- 
 out, and kephale, the head), include all those shell-fish 
 that are commonly eaten, as the oyster, muscle, 
 cockle, and clam, all inhabitants of water. 
 
 The Gasteropoda, or belly-footed (from gaster, the 
 stomach, and pous, the foot), are always found in a 
 one-valve, or univalve shell, and include the slug, 
 snail, and the univalve shell-fish, all of which have the 
 power of increasing and repairing their own shell. 
 
 The Cephalopoda, or foot-headed animals (from 
 Jcephale, the head). They have long fleshy arms or 
 appendages, which are generally attached to or sur- 
 round the head. The body in most of these resembles 
 a bag or pouch, to the open end of which the appen- 
 dages are attached, as in the cuttle-fish, nautilus, &c. 
 
 These are common in all seas, but are largest 
 within the tropical, where they are strong enough to 
 eeize animals as large as dogs in their long and 
 strong tentacles. They swim backwards, and with 
 their head either upward or downward. They have 
 two large eyes, and are the only mollusces which seem 
 to have a brain in a gristly box.
 
 ZOOLOGY. 157 
 
 The cuttle-fish contains a black liquid, which it 
 discharges into the water when disturbed, and which 
 is said to be used in making Indian ink. The fossils 
 Bellerophon, Ammonite, and others belonged to this 
 class. 
 
 The paper nautilus is so called because its shell is 
 very thin and light, and it has two tentacles thinner 
 than the others, which can be spread out and hoisted 
 to serve as sails. 
 
 SUE-KINGDOM ARTICTTLATA, 
 
 Articulata, or jointed animals (from articulus, & 
 joint), includes the four classes, Annelides, Crustacea, 
 Arachnids, and Insecta. 
 
 The class Annelides, or Annulata, ringed creatures, 
 (from annulus, a ring) includes all the worm tribe, 
 which are the only animals that have red blood, 
 without being vertebrate or back-boned animals. The 
 body is divided into rings like that of the common 
 worm, with rows of protuberances along the sides of 
 the body. 
 
 With the exception of the earth-worm, all the 
 annelides live in water, and breathe through gills, 
 some of which are inside the body, and some on plume- 
 like branches, springing from the head. 
 
 Examples Earth-worm, leech, sea-worm, and the 
 serpula, which is often found in hollow tubes fixed to 
 other sea animals. 
 
 The class Crustacea, or crust-covered animals (from 
 crusta, a shell), includes all the invertebrate creatures 
 which are covered with a hard shell or skin, and 
 nearly all of which have the power of renewing or 
 reproducing a limb if broken off. 
 
 Familiar examples of this class are the lobster, 
 crab, craw-fish, prawn, and shrimp, the wood-louse, 
 
 U
 
 158 OUTLINES OF SCIENCE. 
 
 sand-hopper, and others. The fossil Trilobite is also 
 one of this class. 
 
 Class Arachnids, or spider-like animals (from 
 arachne, a spider), were formerly classed as insects. 
 They include the various kinds of spider and scorpion, 
 all of which breathe through lungs, and the various 
 mites and ticks, which breathe through air pipes placed 
 on each side of the belly. They have from six to 
 eight eyes, and always eight legs. 
 
 There are numerous varieties of spider, some of 
 which are very large, and all of which are carnivor- 
 ous, or flesh-eaters, and which take their prey in nets, 
 except the mason spider, which constructs a small 
 house, with a trap lid and hinge, lined with a kind of 
 silk. Some dig galleries or pits, and He at the bottom 
 to entrap the unwary creatures which may attempt to 
 cross, and fall to the bottom. 
 
 Scorpions are only found in hot climates, are 
 covered with a hard case, and have a venomous sting 
 in their tails, with which they sting to death locusts, 
 beetles, and other creatures on which they feed. 
 
 Mites are usually very small, like the cheese-mites, 
 and similar creatures are found in the skin of animals, 
 which are suffering from cutaneous or skin diseases. 
 Of the same species are the troublesome tick, which is 
 found on sheep and cattle, and which are called para- 
 sitical, because they hang on them, and suck their 
 blood. 
 
 The harvest spider is placed in this order, because 
 it breathes through air-pipes, which differ from the 
 lungs of the other spiders. 
 
 Class Insecta, or insects (from inseco, to cut), in- 
 cludes many orders composed of creatures of great 
 interest, but too numerous to be particularised here. 
 
 They nearly all undergo three changes before arriv- 
 ing at the perfect state, which those who have kept
 
 ZOOLOGY. 159 
 
 silk-worms will readily understand, as the nature of 
 the change is the same in all. 
 
 The class is divided into nine orders, which are 
 distinguished by the number or form of the wings. 
 They have all not less than six legs, and numerous 
 eyes. 
 
 There are the Coleoptera, or sheath-winged, includ- 
 ing the beetle, death-watch, cockchafer, and others 
 whose wings are covered with a kind of shell. 
 
 Orthoptera, or straight-winged, as the grasshopper 
 and locust. 
 
 Neuroptera, or nerve-winged, to which the dragon- 
 fly, May-fly, and white ant belong. 
 
 Hymenoptera, or membrane-winged, such as the ant 
 and bee. 
 
 Hemoptera, or half-winged, as the aphis and fire- 
 
 fly- 
 
 Keteroptera, or various-winged, as the common bug 
 and water-scorpion. 
 
 Lepidoptera, or scale-winged, which includes all 
 the moths and butterflies. 
 
 Diptera, or two-winged, as the gnat and common 
 
 fly- 
 
 Aptera, or wingless insects, such as the flea. 
 
 In all these names of orders, part of the name is 
 from pteron, a wing. 
 
 Insects abound in countless millions, especially in 
 hot countries, and some of them perform the work of 
 purifiers, by devouring the animal matter which, if 
 allowed to remain, would be the source of pestilence. 
 They will clean the flesh from the skeleton of a dead 
 animal, as neatly as though it had been scraped 
 with a knife. 
 
 142
 
 160 OUTLINES OF SCIENCE. 
 
 QUESTIONS ON CHAPTER XLVI. 
 
 What are included in the sub-kingdom mollusca ? 
 
 Why are they so called ? What are the acephala ? 
 
 Give some examples of the acephala. 
 
 What is peculiar to the gasteropoda ? 
 
 What remarkable power have they ? 
 
 Describe the cephalopoda. Some examples. 
 
 What is remarkable about the cuttle-fish ? 
 
 Why is the nautilus so called ? 
 
 How is the sub-kingdom articulata divided ? 
 
 What are the annelidse? Where do they live? 
 
 To what class does the lobster belong ? 
 
 What remarkable power have the crustaceae? 
 
 Give some examples of arachnidae. 
 
 What is peculiar in their structure? 
 
 Which of them are called parasitical ? Why ? 
 
 Why is the class insecta remarkable? 
 
 What are the coleoptera ? What is pteron ? 
 
 To which orders do the bee, moth, and flea belong ? 
 
 Give examples of diptera, neuroptera, heteroptera. 
 
 What groat duty do the insect tribes perform ? 
 
 CHAPTER XLVII. 
 SUB-DIVISION VERTEBRATA. 
 
 The vertebrate animals are divided into four great 
 classes, fishes, reptiles, birds, and mammalia, or Pisces, 
 Reptilia, Aves, and Mammalia. 
 
 These have a backbone containing the spinal mar- 
 row, the chief centre or trunk of the nervous system, 
 which is the foundation of the division. 
 
 Class Pisces, or fishes, (from piscis, a fish) all live in 
 water, and are produced from eggs or spawn. They 
 breathe through gills, and are cokl-blooded, and have 
 an air-bladder. They are arranged in two orders, 
 Cartilaginous, or gristly, and Osseous, or bony, accord- 
 ing to the nature of the vertebra.
 
 ZOOLOGY. 161 
 
 The Cartilaginous tribes have the skeleton in one 
 piece, and are either fix-gilled, as in the shark or 
 lamprey, or free-gilled, as in the sturgeon and skate. 
 
 The Bony fish form four orders, according to the 
 structure of the fins : the Thorny-rayed, as the perch, 
 flying-fish, and gurnards ; the Soft-T&jed, as the carp, 
 salmon, and herrings, cod-fish, flounder, and other flat 
 fish, eels of all kinds ; the Tufted-gilled, as the sea- 
 horse and pike-fish ; and the Pledognathi, or cheek- 
 joined, such as the saw-fish and globe-fish, which have 
 the cheeks or cheek-bones in one piece. 
 
 The form of all these creatures is best adapted for 
 moving in the water, and they furnish many instances 
 of design. 
 
 All the flat-fish have the eyes on the upper side, and 
 that side is of a darker colour than the other, so as to 
 be less easily seen by others which prey upon them. 
 
 All are nearly of the same specific gravity as water, 
 so that a slight inflation or pressure on the air-bladder, 
 will cause them to rise or fall in the water. 
 
 Class Reptilia, or reptiles, (from repo, to creep). 
 These are so called from their creeping mode of walk- 
 ing ; they are cold-blooded, and slow in respiration or 
 breathing. 
 
 Eeptiles are oviparous, that is, produced from eggs 
 or spawn, grow slowly, sleep much in cold climates, 
 and usually live to a great age. 
 
 Like the lowest class Radiata, many of them have 
 the faculty of reproducing limbs if broken off, or an 
 eye if taken out, and are remarkably tenacious of life. 
 Some, as the frog for example, will live a long time 
 after the brain has been removed from the head, while 
 a tortoise will live for weeks without any head at all. 
 
 Reptiles are divided into four very distinct orders : 
 Chelonia, Sauria, Opludia, and Batrachia. 
 
 The order Chelonia (from cMys, a tortoise) includes 
 
 H 3
 
 162 OUTLINES OF SCIENCE. 
 
 all the tortoise and turtle tribes, which are enveloped 
 in a hard shell composed of two plates, often of great 
 strength. They have no teeth, but the jaws are so 
 hard, that they are able to bite through shrubs and 
 the toughest vegetables. 
 
 Most of the tortoises proper are found on land, 
 though a few inhabit both land and water. The 
 turtle, or marine tortoise, lives in the sea, but comes 
 frequently to shore to lay its eggs in the sand, and to 
 feed. 
 
 One species, the hawk's-bill turtle, furnishes the 
 fine tortoise-shell which is so valuable in commerce, 
 and which is separated from the creature by a cruel 
 roasting process, while the animal is alive. The turtle 
 of the Galapagos islands, and of other tropical parts, 
 affords excellent food, and a good oil is obtained from 
 its flesh. 
 
 The order Sauria, or lizard-like animals, (from 
 saura, a lizard) includes the crocodiles, chameleons, 
 geckos, which have the singular power of adhering 
 by their peculiar sucker-like feet to the ceiling of a 
 room ; iguanas, which are remarkable for their large 
 size, and a leathery membrane, which enables some of 
 them to make long leaps from tree to tree ; the true 
 lizards, such as have a loose forked tongue, and five 
 toes on all the feet ; and the skinks, which are more 
 snake-like in form than the others. The last are able 
 to burrow into the sand with great rapidity. 
 
 The order Ophidia, or serpent-like, (from ophis, a 
 serpent) includes all the snake and serpent tribes. 
 Nearly all are destitute of limbs, though a few have 
 little bones beneath the skin, which look like the 
 rudiments of limbs. 
 
 In all the true serpents the ribs pass completely 
 round the body, the jaws are movable and easily sepa- 
 rated, so that these creatures can swallow others of 
 larger size than themselves.
 
 . 163 
 
 Few of them in comparison are poisonous. Those 
 which are so, are furnished with two fangs, or long 
 hollow teeth, and at the base of each hollow there is a 
 spongy gland, which when pressed yields a poisonous 
 fluid, that passes down the groove of the teeth into 
 the wound made by the serpent. 
 
 These fangs, when not in use, fall backwards to the 
 roof of the mouth, so as not to be in the way while 
 food is being swallowed. 
 
 The order BatracMa, or frog-like animals, (from 
 batrachos, a frog) include frogs, toads, the salamander, 
 proteus, and siren. The frog tribes pass through some 
 curious changes before attaining their true shape. 
 The spawn or egg becomes a tadpole, which is fur- 
 nished with gills for breathing purposes, and which 
 fall off when the animal changes from the tadpole into 
 a frog or toad. They feed chiefly on insects. 
 
 The salamander, proteus, and siren, are in form 
 more like the saurians, but they undergo similar 
 changes to the other Batrachians. They are found 
 chiefly in mines, or other subterranean passages. Some 
 gigantic fossils of the salamander have been found in 
 Germany, and parts of them in England. 
 
 How is the sub-kingdom vertebrata divided ? 
 
 What is said of all these classes ? 
 
 What is said of the blood of fish and reptiles ? 
 
 Row are they produced ? How divided ? 
 
 What are cartilaginous fish ? An example. 
 
 How are bony fishes arranged? 
 
 G-ive an example of each of the four orders. 
 
 What is said about the form of fishes ? 
 
 What are the orders of the class reptilia P 
 
 What is included in the chelonia ? 
 
 Whence is tortoise-shell obtained ? 
 
 What are included in the order sauriaP 
 
 Name some peculiarity of the gecko and iguana.
 
 164 OUTLINES OF SCIENCE. 
 
 To what order do the serpents belong ? 
 
 Describe the mode of poisoning in serpents. 
 
 What are included in the order batrachia ? 
 
 Through what changes does the frog pass ? 
 
 Why ia the salamander placed with the batrachians ? 
 
 CHAPTEE XLVIII. 
 
 CLASS AVES. 
 
 This class (from avis, a bird) are all oviparous and 
 warm-blooded, with a complete double circulation, are 
 nearly all covered with feathers, and are bipeds, or 
 two-footed. 
 
 Birds have air cells in their bones, which communi- 
 cate with the lungs, &c., by which their specific 
 gravity or weight is lessened, and the lungs are fas- 
 tened to the cavity of the chest. 
 
 As they have no teeth, they are furnished with a 
 powerful muscular apparatus called the gizzard, which 
 in some of the class is so powerful, as to grind down 
 metallic substances. 
 
 In all birds the eye is formed for distant sight, and 
 in some it is covered with a third eyelid, called the 
 nictitating membrane ; this is drawn forward by the 
 bird at will, and forms a sort of screen to the eye, by 
 means of which the sight of eagles, hawks, and other 
 birds of prey is preserved and strengthened. 
 
 Birds are divided into seven orders, viz. : Accipitres, 
 Passeres, Scansores, Gallinacece, Grallce, Cursores, and 
 Palmipedes. 
 
 Accipitres, or hawk-like, (from accipiter, a hawk). 
 These are also called raptores, or plundering birds, 
 because they are all birds of prey.
 
 ZOOLOGY. 1G5 
 
 They are distinguished by their hooked beak and 
 claws, and have strong muscular powers of wing. 
 
 They are divided into Diurnal birds, such as the 
 eagle, vulture, hawk, falcon, buzzard, secretary, and 
 kite, which fly by day, and the Nocturnal raptores, as 
 the owl. 
 
 The nocturnal birds are singularly adapted for silent 
 hunting by night. Their eyes are large, so that they 
 receive every ray, and the feathers are so soft and 
 downy, that they make scarcely any sound in flying. 
 
 All the accipitres are solitary, and seldom lay more 
 than two eggs. Were it otherwise, they would multi- 
 ply, so as to destroy too many of the smaller creatures 
 on which they prey. 
 
 The buzzard and vulture are useful in tropical 
 climates to clear away the dead bodies of animals and 
 other garbage. The rest feed only on living prey. In 
 Egypt the common vulture acts as a useful scavenger, 
 hopping about the streets feeding on garbage. On 
 this account it is protected by law, like the stork in 
 Holland, which serves a similar purpose. 
 
 Order Passeres, or sparrow-like birds, (from passer, 
 a sparrow) are also called insessores, or perching birds. 
 This order comprises numerous varieties, which differ 
 in many respects, but are all perchers. 
 
 They are Fissirostres, or wide-mouthed birds, such 
 as the night-jar, swallow, kingfisher, and others, which 
 catch their insect prey as they fly with open mouths ; 
 all these have short legs, and generally weak feet. 
 
 Dentirostres, or tooth-billed birds, as the butcher- 
 bird, thrush, fly-catchers, and warblers. These have 
 a notch or tooth on each side of the upper mandible 
 of the bill. 
 
 Conirostres, or cone-billed birds, as the starling, 
 sparrow, lark, crow, various finches and others, which 
 feed chiefly on grain.
 
 166 OUTLINES OF SCIENCE. 
 
 Tennirostres, or thin-billed birds, as the humming- 
 bird, sun-bird, and hoopoes. These frequently have 
 the tongue divided at the tip, to aid them in sucking 
 honey from flowers. 
 
 Some naturalists have arranged them differently, 
 but the above is more convenient than any other. 
 
 Scansores, or climbers, compose the third order. 
 Instead of having three toes in front and one behind, 
 as is the rule, the climbers have two toes in front and 
 two behind, by which they are enabled to grasp more 
 easily whatever they wish to climb or hold. This 
 includes the parrot, toucan, wood pecker, tree-creeper, 
 and cuckoo. 
 
 Galliaaceae, or fowl-like (from gallina, a hen). This 
 order comprises the common fowl in all its varieties, 
 pheasant, grouse, turkeys, pea-fowl, and the pigeons. 
 
 These are all useful to man, and some varieties, like 
 the cad-chewing animals, are found wherever man is 
 found. They are gregarious, lay many eggs, and are 
 granivorous, or grain-devouring. They are more 
 capable in walking and running than in flying, and 
 because of their habit of scraping or scratching the 
 ground, they are sometimes called Rasores, or scrapers. 
 Many of the most valuable have been reclaimed from 
 the wild state. 
 
 The Columbse, or pigeon family, are sometimes 
 placed in a distinct order, because they differ somewhat 
 from the rest of the Gallinacese. They breed in pairs, 
 lay only two eggs for a hatching, and feed their young 
 ones from their own crop, in which ihey soften the 
 grain to prepare it for them. 
 
 Grallatorse, or Grallae, stilted birds (from grallce, 
 stilts), compose the fifth order. These are all wading 
 birds, long-legged and long-necked ; they all usually 
 have the bill long, and fitted for searching the waters 
 for food.
 
 ZOOLOGY. 167 
 
 The chief examples of this order are the stork, heron, 
 lapwing, crane, snipe, and other similar long-legged 
 birds. 
 
 They feed chiefly on small fish or reptiles, and in 
 Holland the stork is protected, as being very valuable 
 in destroying reptiles and noxious insects. 
 
 Cursores, or runners. By some naturalists the 
 ostrich, emeu, cassowary, apteryx, and the extinct 
 dodo, are classed with the Grallse, but they are more 
 properly called Cursores, or runners. 
 
 They do not fly, for their wings are not sufficiently 
 long, though they make use of them in running. 
 
 In some of them, as the emeu of Australia, and the 
 apteryx of New Zealand, the feathers look more like 
 hair, and their food is obtained in an entirely different 
 mode from that of the Grallae. 
 
 Palmipedse, or web-footed birds (from palma, a palm), 
 includes all the really web-footed swimming birds. 
 This order is sometimes called also Natatores, or 
 swimmers. 
 
 It includes all the flat-bills, such, as ducks, geese, 
 and swans ; the completely webbed, as the pelican ; 
 the long-winged, as the albatross, gull, tern, and petrels ; 
 and the short-winged, as the penguin, auk, puffin, and 
 various divers. 
 
 Some of these, as the petrel and albatross, live 
 entirely on the sea, while others live partly on land, 
 and inhabit the rocky coasts and islands of distant 
 parts of the world. 
 
 QUESTIONS ON CHAPTER XLYDL 
 
 Name the peculiarities of the class avea. 
 What have they instead of teeth ? 
 What is the nictitating membrane ? 
 How is the class aves divided ? 
 Which belong to the diurnal acc'pitres ?
 
 168 OUTLINES OF SCIENCE. 
 
 How are the nocturnal birds adapted for hunting P 
 
 How are the vulture tribe found useful? 
 
 How are the sparrow-like birds arranged? 
 
 To what sub-order do the swallow and thrush belong 
 
 What are those called which feed on grain ? 
 
 What is remarkable in the climbers ? 
 
 Which order is most useful to man ? 
 
 Give some description of the gallinse? 
 
 Why are they sometimes called rasores ? 
 
 In what do pigeons differ from the rest ? 
 
 What are included in the grallatorse ? And win ? 
 
 Where is the stork found very useful ? Why ? 
 
 To what order does the ostrich belong ? 
 
 What is curious in the emeu and apteryx ? 
 
 In what order are the flat-billed birds ? 
 
 Name some differences in the birds of this order. 
 
 CHAPTER XLIX. 
 
 THE CLASS MAMMALIA, 
 
 The class Mammalia (from mamma, a breast or 
 pap), includes all those animals which have a complete 
 double circulation of warm blood, and are viviparous, 
 that is, which produce their young alive, and which 
 moreover suckle them with milk, until able to provide 
 food for themselves. 
 
 This class is divided into nine orders, viz. : Bimana, 
 Quodrumana, Carnaria, Harsupialia, Rodentia, Edentata, 
 Pachydermata, Ruminantia, and Cetacea. 
 
 Order Bimana. This order (from Ms, two, and 
 marnis, a hand,) includes man only, who alone of all 
 creatures can rightly be called two-handed. As we 
 shall enter minutely into the structure of man in 
 Human Physiology, further mention of it here is 
 omitted.
 
 ZOOLOGY. 169 
 
 a hand). In this section all the ape, monkey, and 
 lemur tribes are included. They are called four- 
 handed, because what is usually looked upon as the 
 hinder foot, is really a hand. 
 
 The thumb is placed opposite the fingers, and not 
 beside them in all the four limbs, and the fingers are 
 long and flexible, so that the quadrumana can grasp as 
 readily with one hand as the other. As they swing 
 about much on trees in their search after food, this 
 arrangement is a great convenience to them. 
 
 Some writers have shewn a desire to prove that 
 this order is nearly identical with the order Bimana. 
 
 In spite of their intelligence, however, the structure 
 of the skeleton in the ape, as well as the rest, shows 
 that they are quite distinct from man. 
 
 Apes are destitute of tails, baboons have short ones, 
 and monkeys generally long ones, and frequently pre- 
 hensile, that is they are able to use them as a hand to 
 grasp the branch of a tree, &c. 
 
 The lemur is found in Madagascar, and is nocturnal ; 
 it is also more slender and delicate than others of the 
 order. The monkey tribe are nearly all fruit-eaters, 
 and are themselves roasted aud eaten with relish in. 
 South America. 
 
 Order Carnaria (from carnarius, a butcher), includes 
 all the killing animals. They may be known by the 
 formation of the teeth, which are only formed for 
 cutting and tearing food, and not for grinding it, as 
 in the vegetable and grain eaters. 
 
 This is a very extensive order, and includes very 
 various cre^tures^ and it is usually divided into five 
 great families, which are themselves so large, that some 
 naturalists give them a separate order. 
 
 They are Cheiroptera, or hand-winged ; Insectivora, 
 or insect eaters ; Plantigrada, or foot- walkers ; Digiti- 
 grada, or toe- walkers ; and Amphibia, The last three 
 compose the true carnivora, or flesh-devourers. 
 
 15
 
 170 OUTLINES OF SCIENCE. 
 
 Cheiroptera (from cheir, a hand, emdpteron, a wing), 
 includes the bat tribes, which are found in all tempe- 
 rate and tropical climates. They are distinct from all 
 other creatures, in having a body similar to that of a 
 mouse, while the limbs are connected by a leather-like 
 membrane, which when spread, serves them as wings. 
 
 In the East Indian Islands there are bats of large 
 size, which are fruit-eaters, and in South America 
 others which suck the blood of animals, and are called 
 vampire bats. 
 
 Insectivora (from insecta, an insect, and wro, I 
 devour), includes the mole, hedgehog, shrew, musk- 
 rat and tenrec, all of which are insect-eaters. 
 
 Plantigrada (from planta, the sole of the foot, and 
 gradus, a step), include all the bear tribes, the racoon, 
 glutton, ratel, and badger, which plant the whole foot 
 on the ground ; the footstep of the bear in the snow is 
 easily mistaken for that of a man. 
 
 Digitigrada (from digitus, a finger), include all those 
 that walk on the toes, viz. : the dog tribe, with the 
 wolf, fox ; the cat tribe, with the lion, tiger, jaguar, 
 leopard, and the common cat, weasel, polecat, and 
 many others. 
 
 The cat tribe have their claws in a sheath, which 
 keeps them always sharp, with a soft ball under each 
 toe, and one under the foot. Nearly all of them take 
 their prey by springing upon it. 
 
 The dog tribe have the claws always unsheathed, 
 and hunt their prey down in packs. 
 
 Amphibia (from amphi, both, andfws, life), includ.es 
 all the varieties of seal. 
 
 Order Marsupialia (from marsupium, a pouch), in- 
 cludes the kangaroo, opossum, wombat, ornithorynchus, 
 and others, that are furnished with a belly-pouch, in 
 which the young ones are carried and suckled until
 
 ZOOLOGY. 171 
 
 strong enough to take care of themselves. Except the 
 opossum, they are all peculiar to Australia. Most 
 remarkable of them all is the ornithorynchus, or duck- 
 billed platypus, which has a body somewhat like a 
 beaver, though smaller, with the bill of a duck, webbed 
 feet, and spur on the heel. The kangaroo is herbi- 
 vorous, but the others are insectivorous. 
 
 Order Rodentia (from rodo, I gnaw), comprises those 
 animals which have two long front incisors, or cutting 
 teeth, in each jaw, and no tearing teeth, such as the 
 rat, rabbit, squirrel, beaver, porcupine, and many 
 others. 
 
 All these have greater strength in the hinder than 
 in the fore legs, and some, as the squirrel and beaver, 
 make use of their fore-paws as hands. All are herbi- 
 vorous, and many feed on roots 
 
 QUESTIONS ON CHAPTER XLIX. 
 
 How does class mammalia differ from the other classes? 
 
 How is it arranged ? Where is man placed ? 
 
 What are included in the quadrutnana ? And why ? 
 
 How do apes, monkeys, and baboons differ? 
 
 Where is the lemur found ? 
 
 In what order are the chief beasts of prey ? 
 
 How may they be known ? 
 
 Into how many great families are they divided ? 
 
 What are the cheiroptera ? Why so called ? 
 
 W T here are the bat tribe found yery large ? 
 
 To what family do the mole and hedgehog belong? 
 
 What is meant by plantigrada ? 
 
 What animals belong to the digitigrada ? 
 
 What is remarkable in the cat tribe ? 
 
 What is meant by amphibia ? 
 
 What is peculiar to marsupialia ? 
 
 Where are they found ? With what exception P 
 
 Which is most remarkable of the marsupials ? 
 
 In what order are rabbits included ? Why ? 
 
 What is said of the legs of the rodentia ? 
 
 152
 
 172 OUTLINES OF SCIENCE. 
 
 CHAPTER L. 
 
 MAMMAIIA continued. 
 
 Order Edentata (from e, without, and dens, a tooth), 
 includes those animals which have no front teeth, that 
 is, no incisors, and sometimes no tearing teeth, as the 
 sloth, armadillo, and ant-eater. 
 
 The sloth feeds on the leaves and small branches of 
 trees, and is curiously slow in its movements ; the 
 others feed chiefly on ant-hills and putrid flesh. They 
 are found only in South America, where they are 
 eaten by the native Indians. 
 
 The armadillo is covered with a hard, striped, 
 shell-like armour, and like the ant-eater, is entirely 
 destitute of teeth. 
 
 The ant-eaters obtain their food by laying their long 
 slimy tongue in the path of the ants, which are caught 
 by the slime, and eaten by the ant-eater. Several 
 gigantic fossil specimens of this order have been 
 found, which have been called the megatherium, or 
 great beast, and the megalonyx. These are of the 
 sloth tribe. 
 
 Order Pachydermata (from pachus, thick, and dermis, 
 the skin), comprises a great number of animals, many 
 of which are very large, as the elephant, rhinoceros, 
 hippopotamus, taper, common hog, horse, and all the 
 zebra and ass tribes. They have all a very thick 
 skin. 
 
 The elephant differs from the rest in having a hollow 
 trunk or proboscis, which no other extant animal has. 
 The horse, ass, and zebra families are distinguished as 
 solipeda, or solid-footed, because they differ from the 
 rest in having the hoof undivided. 
 
 None of this order chew the cud, though they are
 
 ZOOLOGY. 173 
 
 all granivorons or herbivorous, and some, as the 
 hippopotamus, are a great scourge to the rice and 
 corn fields in countries where they abound. 
 
 Order Rnminantia (from rumino, to chew the cud). 
 This order is one of the most valuable to man, as all 
 the animals which compose it are useful in various 
 ways. It includes all those which divide the hoof and 
 chew the cud, or ruminate. 
 
 Except the camel, they have no front teeth or 
 incisors in the upper jaw, but they are provided with 
 four stomachs for the purpose of completely digesting 
 their vegetable food. 
 
 They have the power of returning the food in small 
 parcels from the second or honey-combed stomach, to 
 the mouth, to be chewed a second time. 
 
 It contains two families, the horned and the horn- 
 less ; the latter contains the camels, musk-deer, llama, 
 and vicugna. 
 
 The horned ruminants comprise oxen, deer, sheep, 
 goats, antelopes, and giraffes. The antelopes differ 
 from the deer in having hollow horns. Many of these 
 labour for man while living, and supply him with food 
 and clothing when dead. 
 
 The foot of the camel is unlike that of other rumi- 
 nants, as it is large, broad, and spongy, so that it does 
 not sink into the sand. 
 
 The foot of the reindeer opens widely to prevent 
 that animal sinking into the snow over which it passes. 
 Wherever man can live, there some ruminating animal 
 is to be found. 
 
 Order Cetacea (from cetus, a whale). The ninth 
 and last order of the class Mammalia, includes the 
 whale, narwhal, dolphin, porpoise, and other whale- 
 like animals. 
 
 They have more blood than other animals, as well 
 as a larger amount of fat under the skin, which makea
 
 174 OUTLINES OF SCIENCE. 
 
 them lighter in the water, and is thought to enable 
 them better to bear pressure. 
 
 They have also the power of forcing water through 
 a hole in the upper part of the head, on which account 
 they are sometimes called blowers. 
 
 By common error whales have been called fish, but 
 as fish are cold-blooded, and produced from eggs, while 
 the Cetacea are warm-blooded, and suckle their young, 
 the distinction is plain. 
 
 Cuvier placed among the Cetaceans the manati and 
 dugong, two vegetable eaters, which are found in the 
 eastern seas and in the Atlantic. They are eaten by 
 the Malays, and have very much the appearance of 
 small whales, but are without the orifice in the head, 
 and have less blubber or fat. 
 
 From the above outline it may be seen that the 
 range of Zoology is very extensive, and few persons 
 can give attention to all its branches. It is divided 
 into various branches, each of which affords abundant 
 materials for observation. 
 
 The principal divisions of the science are Conchology 
 (from conJce, a shell), the science of shells and shell-fish ; 
 Entomology (from entoma, an insect), the study of 
 insects ; Ichthyology (from ichthus, a fish), the study of 
 fishes ; Ornithology (from &)-nis, a bird), the study of 
 birds ; and Zoophytology, the study of the plant animals. 
 
 QUESTIONS ON CHAPTER L. 
 
 What is remarkable in the edentata ? 
 What exception is made in the order ? 
 Describe the armadillo and ant-eater. 
 What great fossils are of this order ? 
 What is meant by pachydermata ? 
 Which are called solipeda ? And why ?
 
 ZOOLOGY. 175 
 
 How does the elephant differ from the others ? 
 
 Which order is most valuable to man ? 
 
 Why are they called ruminants? 
 
 Which are the hornless ruminants ? 
 
 How does the camel differ from the others ? 
 
 What is remarkable in the reindeer ? 
 
 Where are the ruminants found ? 
 
 What animals compose the last order ? 
 
 What is said of the blood and fat of the cetacea ? 
 
 What error lias been common about whales ? 
 
 Show how they differ from fishes. 
 
 What is meant by conchology ? 
 
 What science describes insect life ? 
 
 How are the studies of birds and fishes named? 
 
 What is aoophytology ? Why so called?
 
 INDEX. 
 
 PAGE 
 
 Acetic acid ' 90 
 
 Acrogense 56 
 
 Affinity 60 
 
 Alchemy 58 
 
 Alcohol 98 
 
 Aluminium 74 
 
 Annelides 157 
 
 Annual motion 10 
 
 Antimony 75 
 
 Arachnidae 158 
 
 Arsenic 75 
 
 .Articulata 157 
 
 Arteries 149 
 
 Astronomy 4 
 
 Aves 164 
 
 Batrachia 163 
 
 Bile 143 
 
 Bimana 167 
 
 Botany 27 
 
 Butter 94 
 
 Caloric 127 
 
 Calyciflorse 51 
 
 Caoutchouc 95 
 
 Capillaries 149 
 
 Carbonic acid ... ,69 
 
 PAGE 
 
 Carnaria 169 
 
 Cetacea 173 
 
 Chemistry 58 
 
 Chlorine 67 
 
 Chronometers 13 
 
 Circulation 146 
 
 Copernicus 6 
 
 Copper 77 
 
 Corolliflorse 53 
 
 Creosote 90 
 
 Cryptogamiae 46 
 
 Crustacea 158 
 
 Cursores 167 
 
 Dew 135 
 
 Digestion 141 
 
 Diurnal motion 8 
 
 Earth 7 
 
 Eclipses 15 
 
 Edentata 172 
 
 Electricity 100 
 
 EndogensB 55 
 
 Exogense 40 
 
 Firedamp 70 
 
 Fixed E tars... , 26
 
 INDEX. 
 
 177 
 
 PAGE 
 
 Fixed oils 93 
 
 Fossils 123 
 
 Freezing mixture 135 
 
 Gallinee 1G6 
 
 Galvanism 108 
 
 Gases, The 65 
 
 Geology 115 
 
 Glass 85 
 
 Gold 9 
 
 Gum 97 
 
 Gun cotton 99 
 
 GuttaPereba 96 
 
 Heat 127 
 
 Heart, The 146 
 
 Hydrogen 66 
 
 Ice 132 
 
 Insectae 158 
 
 Iodine , 72 
 
 Iron 79 
 
 Jupiter 23 
 
 Latitude 14 
 
 Lead 81 
 
 Lightning 106 
 
 Longitude 13 
 
 Magnesium 81 
 
 Magnetism 112 
 
 Mammalia 168 
 
 Mars 22 
 
 Marsupialia 170 
 
 Mercury 21 
 
 Metals 74 
 
 Mollusca 156 
 
 Monoc-lilamydeae 54 
 
 Moon, The 17 
 
 Mosses 47 
 
 Muscles, The 139 
 
 Natural system 44 
 
 Neptune , 25 
 
 Nitrogen 66 
 
 Nutrition 144 
 
 Ophidia 162 
 
 Organic chemistry 88 
 
 Oxalic acid 89 
 
 Oxygen 65 
 
 Fachydermata 172 
 
 Palmipedes 167 
 
 Pancreas 151 
 
 Passeres 165 
 
 Perspiration 150 
 
 Pisces 160 
 
 Planetoids 7 
 
 Plants 28 
 
 Plant food 32 
 
 Plaster of Paris 76 
 
 Platinum 83 
 
 Porcelain 85 
 
 Potassium 84 
 
 Physiology 137 
 
 Quadj-umana 168 
 
 Eadiata 153 
 
 Eeptilia 161 
 
 Rocks 116 
 
 Eodentia 171 
 
 Kuminantia 173 
 
 Safety lamp 71 
 
 Saliva 141 
 
 Saturn 24 
 
 Sauria 162 
 
 Scausores 166 
 
 Seasons 11 
 
 Secretions 149 
 
 Silver 86 
 
 Skin, The 139 
 
 Soap 94 
 
 Solar System 5 
 
 Starch 97 
 
 Stomach, The 141
 
 178 
 
 INDEX. 
 
 Sugar 
 
 97 
 
 Sulphur ..................... 73 
 
 Tears ........................ 150 
 
 Teeth ........................ 140 
 
 Tides, The .................. 14 
 
 Tin ........................... 86 
 
 Thalamiflorse ............... 49 
 
 Thermometer ............ 133 
 
 Uranus ........... , 25 
 
 Urea 
 
 89 
 
 Urine 151 
 
 Venus 22 
 
 Ventilation 129 
 
 Vertebrata 160 
 
 Vulcanite 95 
 
 Zinc 87 
 
 Zoology 153 
 
 Zoophytes 154 
 
 THE END.. 
 
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