Life: its Forms and Varieties.

Hawke's Bay Weekly Times, Volume 1, Issue 35, 26 August 1867, Page 210

Life: its Forms and Varieties.

A LECTURE, BY Db. JAKINS. ; [|We take the report of the following interesting and instructive lecture delivered by Dr. Jakins on the 12th, before the Young Men’s Christian Association at Auckland from the New Zealand Herald/

Mr Chairman, ladfies and Gentlentan,—A fortnight ago I was asked, to deliver a lecture before this Association., At the time I (asl daresay many others have' been) .was puzzled to know upon what theme to address you. As it wasneeessary to appoint some title, I was induced to 'adopt a comprehensive one, and so I stand before you this evening, to say a few words on the subject of “ life, its Forms and Varieties." Tue time alioted me has prevented my preparing a disquisition on this important topic, even had I the ability; yet so many germ thoughts suggest themselves that I trust each person here to-night may he able to select and carry away such ideas as may suit the peculiar characteristics of his mind, and that the result oi such selection may he manifest in study being directed aud observation being recorded regarding this subject, in which, practically, we are so deeply concerned. 1 shall not trouble you with reciting of authorities, nor will I perplex you with many scientific terms, and if 1 am somewhat homely in my expressions or illustrations it will be because £ wish to render myself intelligible to all.

Life, in its strict sense, we take to be a faculty which is contained in certain bodies, which gives them the power of enduring for a time, and under a special form; which gives them the power of continually appropriating to themselves a part of their surrounding substances, and of rendering back again part of their own snbstances. Living or organised bodies differ from minerals, in deriving their origin from parents, and being able to maintain themselves; they also receive their food into them, while minerals increase by adding to their outsides; organised bodies contain solids and liquids, minerals,do not. This is what science tells us as to the nature of life and living things; but are we any the wiser for it ? it is a faculty with certain attributes; yes, we all know that, but what does it mean ? Are not these scientific definitions but too frequently a learned way of removing the difficulty one step backwards, and in reality no explanation at all P Our forefathers defined life as the blood, and rightly, for as long as the blood or sap lives, so long is the creature alive, when the blood coagulates or ceases to move, it dies, and the creature is dead. Some years ago, when galvanism was much engaging the minds of scientific men, when they saw the spasmodic life-like movements produced upon dead animals by this agent, it was thought that life in its essence was of the nature of galvanism; since that time many improvements have been made in scientific instruments, and, occasionally much thought has been given to the subject. A consideration of a few of these principal facts resulting from those investigations, will perhaps, give us some idea of what life (the breath of life) is. Some of you have perhaps seen a horse suddehly fall dead, you have gone up to it, and you have soon been persuaded that life was actually extinct; the heat of the body was there, there was no blood lost, it was still a fluid, all that a few minutes before was working in full order was now still, the breathing had ceased, the heart had stopped, the eye was losing its lustre, you knew that in a few hours the limbs would become stiff, only to relax again and then decay. Now, let us suppose that on your arrival you had introduced underneath the skin the fine wire of a delicate instrument, used for ascertaining the strength of electrical currents, called a galvanometer, had you noticed the clock-like face of this instrument, you would have seen the hand fall, fall, fall till when the limbs stiffened it stood at the bottom of the scale, and so it remained. On your way home, you would have reasoned thus: breathing had ceased, the heart had stopped, yet the electricity was only going, and it was some hours before it utterly departed, and when it did depart the stiflhess was there,- and the instrument was not delicate enough to . distinguish between this rigidity and the relaxation preceding decay. As you thought over all this, and remembered that a shock from a galvanic battery would stir the limbs as if to life again, yon would have imagined that there must be surely some connection between life and what we call galvanism, and I think you would have thought aright that that life was dependent on the pressure of this galvanism, and so your next wish would have been to try this instrument on a living animaL For example, if you had delicately inserted the fine wire under the skin of the leg of a dog, you would have been astonished to. see how high the hand on the dial stood. The dog, however, might object to the restraint you imposed upon him, and he might struggle a little, with the effect of causing the hand bn the dial to fall. Then you would reflect upon the slight decay produced in the flesh by the wear and tear caused by the struggling of the dog, and you would also lobk hack on the last rigidity of the horse, and perhaps some faint idea would occur to you of the similarity of the decay in the dying flesh. If you were to study this subject you would find that the presence of galvanism was necessary for the blood to remain fluid, and you well know coagulation of the blood would cause the heart to stop, and thus produce death. Cold acts by diminishing the production of this galvanism; heat, to a . certain degree, favors its production; so in cold weather we attempt by exercise to increas the' warmth of the body, and thus the galvauism, or, if I may so term it, the nervous power is likewise increased; in hot weather we prefer remaining quiet; in very hot weather less galvanism is produced, and therefore we feel restless and uncomfortable. I have illustrated this subject of galvanism by referring to the animal kingdom, yet there is strong probability that all that I have said would apply equally to plants. So you see we have not indeed found out what the essence of life is; probably we never shall, but this' we have discovered, that the pressure of galvanism is necessary to its existence. Again, by experiment we Know that by causing a current.of galvanism to pass into the sap that has been taken from a plant we can produce tissue like that from which the sap was taken ; also, that by passing.a current into the raw white of an egg we can form fibres, cells, fibrin, and even cartilage. So we imagine we are nearer the mark than were our forefathers, now that we have discovered that galvanism is the motive power, and the actuating principle of life. . , • Sometimes life seems apparently extinct/ so that an organism seems dead, but yet under the favoring influences of warmth and moisture it revives; thus we explain how it is that the'grains of wheat obtained from the tombs of Egyptian mummies, and from some of our early'. British tombs, 'have grown and produced .fruit when carefully tended. In; the. animal kingdom, in like manner, the common snail at the approach of winter retreats - into its shell, and may remain shut up for- years, but when-'heat and moisture homes, as the weather -becomes warm. again,, so does it sally, forth, inco full life. -Many, varieties q£ fish, and some caterpillars .will even bear to be frozen hard like stones, yet on being, thaweid they revive again. In a less degree we flud ■ this condition in the .common frog, which daring the winter lies at the bottom of) a pond, which is perhaps covered with icej. now, the.frog.is an airbreathing animal,>but the ’ extreme cold -far benumbs' it, that it remains;; almost motionless • the action of the water on its skin - is sufflifleiit to purify the blood in the place of breathing/’as the spring advances and the cold disappears, sodoes the. frog begin to; leaye the. water and to enter upon its' full enjoyinentZof life.\- ; ; The dormouse hidesitselfawayinitsholerwithastoreoffood, vrith whlch'it prolongslts sleiepy bxistehce all the winter, unto, the spring. ;Even in manYwe how anathenftndhim Tfb ball entrance; here fobdismotrequired.'ahdebmetimes the;pnly erideneb of life/is the negative-one; viai that jis,-< absent.' : l have nbi doubt some of yon axe .famimr, with, the casebf‘Colonel bnebcoasioh'he didsohsfQfa'twbeniiheht physi- . as : g*theyteD,-

both his heart and his breathing- had stopped? . they were excessively alarmed, thinking him dead; at last; however, without any external assistance,; signs. of -recovery 'gradually set in, andhewaS; soon all right again. The last time he exercised his power of'entrancing himself he dieiLvThe 1 faquirs of India—a sect of religious devotees~will lie in a trance without food for weeks, and yet’ recover, themselves, and this under circumstances’ in .which deception would he impossible., Mesmerism is a form of trance in which the:: control-: ling power of the will seems asleep, thus, a strong, 1 mind seems to master a weaker one, in so far thatf even the evidence of the senses may be perverted, arid the Operator has only to suggest anythingfor’ the person at once to act. It has been successfully used to induce insensibility to pain, in surgical operations on the natives of India, Electro-biology is a kind of self-mesmerism, in which a man earnestly fixes his attention) not. like some philosophers of old, on the pit of his storaabh, bat rather on a circle of metal,' anything else will do equally well; Ms attention: becomes absorbed, and the nervous system ex-, hausted, so that his will, ideas, and . senses'may be interfered with by another person. Son- . nambulism, or sleep-walking, is a trance in wMch' some special portion of tbe brain seems awake, sill the rest asleep; generally the individual walks' well, accomplishes some trifling act, and then re-' turns to bed., There is enough perception for the proper performing of the act, although not usually for recognising anything extraneous or for remembering aught of it on the"morrow. In dreams the imagination alone seems awake; some have said that we dream every night, although we do not always remember our dreams. I think this must only apply to those who overwork, their brains. An odd thing in dreams is. that we do*not seem to have the power of perceiving the absurdity of the fancies that arise, nor can we see a way of getting out of our perplexity, of escaping from what seem actually impending. Again, through what a space of time' can we travel in & dream of hut a few minutes’ duration, it seems as~ if years had sped. In the delirium of fever, and in the stupor of drowning, this occurs in amarkeddegree. I need hardly refer you to the common causes of dreams, indigestion, overtaxed brain, or' the perverted perception produced by sensations occurring during sleep. Catalepsy is also a kiud.of trance, in which there is unconsciousness, with, the limbs stiff and rigid. H ere, as in all varieties of trance, the nervous system is much disturbed, much below par, and for this reason the conditions 1 should not be induced except under medical supervision. Insanity again is nothing but a trance, iu which the will is weak, and the flow of ideas or. of the emotions unusually strong. A person of ordinary strength of mind can frequently turn - the current, and thus momentarily pacify the . madman. Many of the insane are, as mesmerised persons, open to suggestion, to action, whether by word or look. And now as to the universality of life, life is everywhere; its germs, the seeds of it, are float-' ihg about in the very air we breathe, in the* water we drink, in the food we eat, in the dust * under onr feet, in fact everywhere where air' exists do we find life. Even some of our infectious diseases we know, to he spread by germs, floating about in the air. This universality of life causes us to try and shut it out from anything which we wish to keep unchanged. If youtake a glass of distilled water and keep it in your room, you know that after a time its clearness’ disappears, and that if you then examine it with a magnifying glass you will find thousands of ani-, malcules in.it;- you say that the water is in reality it is full of animal life, fall - of life so small that of one variety it would take five hundred millions to stock one drop of water. You. put some cheese in a cupboard, and soon a green' mould appears upon it; you say that the cheese* is decayed, hut your magnifying glass reveals: a crowded forest of vegetable life. Yon let down a plummet into the deep, deep sea, down for ak i quarter of a mile, and you still And life, vegetable;' life; another quarter of a mile and vegetable life does not exist; animal life you will find as deep: down as three miles; below this all is quiet and: still.

It is a startling thought that plants and animate have been living and dying unceasingly for thousands upon'thousands of years, and yet that'their*' descendants are' with us at this day. How it impresses upon us the truth that annihilation is ai' physical impossibility, that death is a mere ces-' sation of life under that peculiar form, but the' beginning of life of another grade Our Saviour , beautifully illustrated this thought when he said, “ except a com of wheat fall into the ground and die it abideth alope. hut if it die it bringeth forth much fruit.” Yes, the grain dies and becomes food for the germ, the living principle it contains, the germ grows into the blade, : the. stalk, the fruit; a worm feeds on the fruit, a pheasant eats: the worm, and we eat the' pheasant, we die, and:' are eaten of the worm; hut what becomes of the. living principle in this' series ? we ; caunot telL ■ What has become of it-iu the thousands upoic thousands of years iu which the untold families of plants and animals have lived and died; yet , still the living principle flows on, yes, flows on iu the hundred thousand families of plants, in the ■ quarter million tribes of animals, and yet the... world is only partly catalogued. .How is it that we find no difference in the characters of tribes of animals now existing as compared with those <■ of three thousand years ago ? In the British Museum at home, on the; Egyptian monuments you> may recognise carvings of animals, reptiles, birds, cats, and oxen like those of the present day; even the lineaments of the Jewish faces there depicted are evidently the same as we may any day see 1 here in Queen-street, so unchanging seems to he the peculiarities of tribes of animal life. I might, . in like manner, refer to vegetable life, had I the time, but I will instead direct your attention ta the fact that all living creatures breathe air. lhe frequency of breatMug and the warmth of an animal are in proportion to the amount of exercise it takes; and so we find bees and birdsmuch wanner than any other animals, they also, in proportion to their size) consume more air, indeed a couple of sparrows require as much air as a Guinea pig. Plants cannot live without air* any more than can animals. Both plants - and- . animals obtain air_in the same manner. In. a. rose tree air enters the sap through the fine skin - covering all parts of the tree. Air is also contained in the water which is taken up by meahs. : . of the roots. In the fish air enters the sap, the blood by being contained in the water which the fish fOl ces over its gills; remove the air from the

water by boiling; and tbe, fish will surely die. Man breathes by the air. entering the blood

through the skin covering his body, but especially ; through' that fine continuation of the skin inside : the body which we call the lungs. - Even an egg requires air, or the living principle within 80ou perishes, so we see the shell drilled with minute; . holes.. I have heard of persons stopping up these holes .by varnishing the egg, in this way pre-;. serving it in good coqflition for some rime, for the. presence of air is necessary for ’ decay, and thus bound up closely and ; inseparably .witM life is.''decay or death, for : just as surely as ih walking .. . the sole of your bootwears, so does the flesh thatmoves the foot, and the nervous system that sets, in action tbe flesh. ' Fortunately repair goes on . in the foot as quickly as decay, and thiis it becomes no smaller; let the repair he in cxcesaand : the foot grows, disorder the repairs of thisbur * body, or let any partofitibe blooked up by the * rubbish caused by : the wear ; and tear. and you; * have disease; .?* excessive \ disorder : or-"excessive:, : ; blocking up stops, the whole machine,. and the -

man is dead. ~ ...v '■.'v'.... Now, how is it that these ioxms of deoay amd repair so naturallybalance Oneanother ? in- other “ words, how- has God arrangedthatall created ' beings should fulfllthe natural terms of their : • existence ? I thinlt Ishall he ableto show you . / that the .source of the contihuance of life is Bgtti£2i light derived sumLet'. .us? begin looking. attheprooessof life as we seerit ia> ■ .jj . v i explain the m sailing - oftwo. words, of which hf i ; shall make firequehtanehtibh;: The ;first is carbon^ 1 , which, exists in foi^' the diam6nd, juflt:aß‘water i9seeh:ihasohdfrt)m' - as ice; :’ The? s^hd^>ro^^uvo3^en , gaibyimeanalofwhiohjtareatedvbeingaicarryron! .>- to?. iji^er;fdrm^earbonib ( iusi^iX6jbl^da ,♦

• • vv *-,*>-i 4 V\^v~t-« a !■■!.,: rr~r. v ; haa fhe poweijrof.diviamgvfiarbonlo add—that gas | - - which ..-. is . fatal.to: all-animal .liferrinto/ carbon, , wMch r tli'ealant rnfor itself, and-by which! it growßj'afid iftifto' set" free; for * ' eTeryTatiitnal thatrl)rea«jesr~>l - B'^t^oji r ttot plaiita 'wiiligEOw:iu'ttio dark, away; * .- from;weTigM,''buttlieiitfieir , fai£LTieaoß>ft)r ; godd is ,: carbonic that some sick folbs are'oftcii forbiddehrto have"ilantsintheirb6drboTEu^'Tert;; 1 : animal life, a.want of. it ;would; carry death £6 all plants,’ .. and soit a of the air ; j we-breathe. It is'in- Warm. wbather that carbonic aoid:is‘so'ahutidiint,Vbecaiisestlien',ferrmMit!ati(ra.. .and decay are so active.,/,®hehot sun in the' day- •. . thtmWe,:flnd : taomcatb‘ohic ardd-atrtiigh't.* -ltfdry weather we notice mor&of it than in wet weather, ■ beeafase ;th%rs4n*dissolYes it it away. 1 Updo a.certain point heat aiicl moistuTe qui cken / the process otlirev thtSH'n a’cliinate Uke'thislall - animal' lifeffiourisheS, • Her; plants, however, 1 attract moisture, fromthe. qlouds.so, climates ate.dry or moist according to 1 the 'amount' of yegetdttbn'dhey contain. A owlions fact in connection with heat l 'as regards • animals is that;spme : flsh are'found lo live in hot, springs;; even of a teffiperatue of 182 deg., a heat ‘ °f deg. above what iß< J necessary to stiffen or coaghlate dhe j albumenvofi l which their flesh is Some caterpillars have been known flouTish' at Ja temperature .‘almost of boiling water, h,nd‘ some worms havd been known to live in spite. of being boiled. Light seems as necessaty for men as for plants, for unless men see the sun occasionally they become pale and sickly. ... Heat, in combinatiou with gooddbo'dvhas rthe-effect of raising.the J;ypo.' of,, developments 0f,..a .creature. -?ft know, the; effects -of a hothouse upon ‘ plants, x j under these some insects, the little'fereen aphis, or .plant-louse, as it has been termed.'wiU bring forth its young alive,-while in the cold.Jweather it. lays eggs*.' Again, common ' beds,.' by 1 , Oxtriii'attention to warmth;',, and the quality nf the foodof their young, cause: them • to grow into queen, bees. -Even in man, look what an improvement is'made in the child of the ontcaat 'or ■of the savage} by careful nurture.- with good food andclotbing. *• To return, to plauts; -it . is. through.absorbing and .decomposing, the-car-bonic acid that, thedeaf becomes green; stop'this process and the leaf at ouae takes -up oxygen;, and •becomes red. Fruit in the same way; when it ceases to take up carbonic acid begiDs-to.take up oxygen, and thus becomes acid, and gradually vedj'-ripeneaS is reallytihe stopping of these processes; and the beginning of decay. Hydrogen, another gas, which, when j oined to oxygen.-forras water, eives bitterness- to plants. The actions of "these several gases are well- -exemplified* in one plant—aspecies of navelwort; which in the mom- ■ log’, from the 'accumulation of oxygen absorbed overnight,- tastes-acid; at noon, from the admix-, tnre of oxygen with hydrogen, it is insipid}; at night, from the pecomposition of water, the ’oxygenbeing set' freei : and the hydrogen retained,it thus, from the excess of hydrogen.rtastes hitter. Even." the ,' sunlight, in passing through a , green leaf, is decomposed, for We find that it no longer has the power of. procueing l a photograph on sensitive paper.* 'This is-the'reason why it is «°. difficult to photograph leaves., Plants obtain their food from the carbonic acid and the moisture of the atmosphere, 1 by' means of their .fine skin an d* their roots, which - chiefly -absorb, water, and •decayed animal and vegetable matter. The pro--cess of absorbing one gas abd giving out another, , is like the bre'athihg of animals; the upward eir- - oulation of the sap resembles the cireulationof the blood; tie root of the plant seems especially concerned in digestion, and, as iu animals, all indigestible food is castout. In these processes, as in the process of life in the animal kingdom, heat was: induced, electricity is formed, negative electricity; positive electricity occurs more frequently in animals. Animals are depressed sin thunder weather: plants are refreshed and invigorated. With the sensitiveness of-some plants .you are familiar; some close their flowers in rainy • weather, or at-night, .-as? If going to‘sleep; they, may even be made to sleep with opium, or they may he poisoned uith spirits, or arsenic, ,or. strichiua, 1 or their constitutions maybe .improved by a course of iron. The fall of the leaf is due, to the .blocking up, of the circulation of the sap, an - • obstruction whioh is caused by a: want of removal 1 of the waste , caused by the wear. aud;tear of the life .of the.leaf. Like men,, plants have their ' diseases,-or die-'of old age. It'-was; perhaps, a ( knowledge .of some of these processes that led the ancients, to l pen those • beautiful fables of men being changed into trees, hyacinths,-and daffodils. Plants .-may be said to have their religion, too, for they ever tumtheir faces towards their;God, the sun; their tendril arms seem never tired of stretchmg forward' and upward into the light of his presence. They* have their reward, too, in increase of life, and of growth, and of fragrance, and of -beauty, .an increase-not of graces merely, but also of usefulness,-usefulness in purifyiug the polluted atmosphere iu which they dwell—a blessing to man and a glory to God. One cannot understand, indeed-it-seems physically- impossible for* a plant to; turn its back upon the sun,'to slink with its tendril arms behind some rock or cover, to poison the already pblluted'atmosphere in. which ' it lives; no, all this:is inscrutably reserved for God’s noblest creature, man. To go back to our subject: -if we observe, the process of life in. animals, we find that tliey.obtain food either.directly from vegetables, or f’rom-hnimals' that have fed. on vegetables. The-carbon of the vegetable, which . -.is taken-up into the .body of.the animal,'becomes, by its union with the oxygen of the air in the act of breathing,'the-source of heat and*m6tion,-or, in other words, of power.; and yet:it is necessary that the oxygen be dilated, or we should, find it too great a stimulant,, and our lives would bum down as quickly as'it candle burns- when- plunged ■ into this -gas,- so -we - find. in -the air. we breathe .that. the. oxygen is combined with four parts of nitrogen.. (To.be continued.)