Life: its Forms and Varieties.

Hawke's Bay Times, Volume XII, Issue 502, 22 August 1867, Page 1

Life: its Forms and Varieties.

frSOM THE NEW ZEALAND HERALD.] The following interesting and instructive lecture on the above subject was delivered by Dr. Jakins, fin the 12th July, before the Young Men’s Christian Association at Auckland:— Mr Chairman, Ladies and Gentleman, —A fortnight ago I was asked to deliver a lecture before this Association. At the time I (itsl daresay many others have been) was puzzled to know upon what theme to address you. As it was necessary 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.” The time alloted 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 io-uight may be able to select and carry away such ideas as may suit the peculiar characteristics of his mind, and that the result oi such self '.Men may bo manifest in study being directed and observation being recorded regarding this subject, in which, practically, wo are so deeply concerned. 1 shall not trouble you with reciting of authorities, nor will I perplex you with many scientific terms, and if I am somewhat homely in my expressions or illustrations it will ha because I wish to render myself intelligible to all.

Life, in its strict sense, wo 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 substances. 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 cer-l tain attributes; yes, we all know that, but what 1 does it mean ? Arc not these scientific definitions but too frequently a learned way of removing the fiilliculty one step backwards, and in realitv no explanation at all ? " ,

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 *nddehly 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 bad stopped, the eye was losing its lustre, you knew that in a lew hours the limbs would become stiff, only to relax again and then decay, Kow, let us suppose that on your arrival you hud 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 baud 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 bad ceased, the heart had stopped, yet the electricity was only going, and it was some hours before it utterly departed, and wbeu it did depart the s'iffaess was there, ami 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, you 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 r life was dependent ou 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 h gh the hand ou the dial stool. The dog, however, mi ..hi object to the restraint you imposed upon him, and he might struggle a little, with the effect of causing the hand on the, dial to fall. Then you would reflect upon the slight decay produced in the flesh by lire wear and tear caused by the struggling of the dog, and you would also look 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 yon were to study this subject you would find that the presence of galvanism was necessary for Uiq. 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, mid thus the galvanism, 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 uncom fortable. I have illustrated this subject of galvanism by referring to tbe animal kingdom, yet there is strong probability that all that 1 have said would apply equally to plants. So you see we have not indeed found out what the essence of life is, probably wo never shall, but this we have discovered, that the pressure of galvanism is necessary to its existence. Again, by experiment we snow that by causing a current of galvanism to pass into the sap that has br-cn taken from a plant we can produce tissue like that liom which the sap was taken ; also, that by passing a current into the raw white of an egg we can fonn fiores, cells, fibrin, and even cartilage. So we imagine we are nearer the mark t han were our forefathers now that we have discovered that galvanism is the motive power, and the actuating principle of life.

6ometimcs life seems apparently extinct, so that an organism seems dead, but vet under the favoring influence? of warmth and moisture, it revives; thus we explain how it is that the grains of wheat obtained from the tombs of Egyptian mummies, aud from some of our earlv Bri.i-b 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 ehut up for years, but when heat and moisture comes, as the weather becomes warm attain, so does it sally forth into full life. Many varieties of fish, and some caterpillars will even bear to he frozen hard like stones, yet on being thawed they revive again. In a lessdcgieewe find this condition in the common frog, which during the winter lies at the bottom of a pond, which is perhaps covered with ice; now, the frog is an airbreathing animal, but the extreme cold su far benumbs it, that it remains almost motionless; the action of the water on its skiu is sufficient to j y purify the blood in the place of breathing; as the! spring advances and the cold disappears, so does' the frog begin to leave the water and to enter' nponiu full enjoyment of life. The dormouse hides ilssi; swsjr is hols mth store of fb n *

nith which it prolongs Its sleepy existence al! the wint-'r unto the spring. Even in man we now and then find him become torpid in what we call a trance, here food is not required, and sometimes the only evidence of life, is the negative one, viz., that decomposition is absent. I have no doubt some of you are familiar with the case of Colonel Townlty, who could throw himself into trance of half an Ilnur’s duration whenever he pleased. On onooccasion ho did so befoio two eminent physicians, who declared that as far as they could tell, 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, and he was soon all right again. The last time he exercised his power of entrancing himself he died. The faquirs of I ndia—- 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 be impossible. Mesmerism is a form of trance in which the controlling power of the will seems asieep, thus, a strong mind seems to master a weaker one, in so far that 1 even the evidence of the senses may be perverted, 1 ard the operator has only to sugge.-t anything for the person at once to act. It has bean successfully used to induce insensibility to pain in surgical operations on the natives of India. Electro-biology is a kind of seif-mesmerism, in which a man earnestly fixes his attention, not like some philosophers of old, on the pit of his stomach, but rather on a circle of metal, anything else will do equally well; his attention becomes absorbed, and the nervous system exhausted, so that his will, ideas, and senses may he interfered with by another person. Sonnambulism, or sleep-walking, is a trance in which some special portion of the brain seems awake, ail the rest asieep; generally the individual walks well, accomplishes some trifling act, and then returns to bed. There is enough perception for the proper performing of the act, although not usually for recognising anything extraneous or lor remembering angbl 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 onr dreams. I think this mast 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 lime can we travel in a [dream of but 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 amarked degree. 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 kind I of trance, in which there is unconsciousness, with the limbs stiff and rigid. ■ ere, as in all varieties of trance, the nervous system is much disturbed, much below par, and for this reason the conditions should not be induced except under medical supervision. Insanity again is nothing but a trance, in which the will is weak, and the ttowof 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, whe ther by word or look. And now as to the universality of life, life is everywhere; its germs, the seeds of it, are floating about in the very air we breathe, in the water we drink, in the food we cat, in the dust under our feet, in fact everywhere where air exists do we find life. Even some of our infectious diseases we know to be spread by germs floating about in the air. This universality of life causes us to try and shut it out from anything which wc wish to keep unchanged. If you lake a glass of distilled water and keep it in your mom, you know that alter a lime its clearness disappears, and that if youthen examine it with a magnifying glass you will find thousands of animalcules in it; you say that the water is decayed, in reality it is full of animal life, full 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, but your magnifying glass reveals a crowded forest of vegetable life. You lot down a plummet into the deep, deep sea. down for a quarter of a mile, and you still find 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 animals have been living and dying unceasingly for thousands upon thousands of years, and yet I hat their descendants are with us at this day. How it impresses upon us the truth that annihilation is a physical impossibility, that death is a mere cessation 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 corn of wheat fall into the ground ami die it ahideth alone, but if it die it briiigeth 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 tlie worm, and we eat the pheasant, wo die, and are eaten of the worm ; hut what becomes of the living principle in this series I- 1 we cannot tell Wh it has become of it in the thousands upon thousands of years in which the untold families of plants and animals have lived and died; yet still the liiing principle flows on, yes, flows on in the hundred thousand families of plants, in the quarter million tribes of animals, and yet the world is only part y catalogued. How is'it that we lied no difference in the characters of tribes of animals now existing as compared with those ol three thousand years ago V In the British Museum at home, on the Egyptian monuments you inay recognise carvings of animals, reptiles, birds, cats, and oxen liketliosc of the present day; even the lineaments of the Jewish faces there depicted are evidently the same as we may any day see here in Queen-street, so unchanging seems to be [the peculiarities of tribes of animal life. I might, in like manner, refer to vegetable life, had I the tune, hut 1 wilt instead direct your attention to the fact that all living creatures breathe air. Ihe frequency of breathing and the warmth of an animal are in proportion to the amount of exercise it taxes ; and so we And bees and birds much warmer than tiny other animals, they also, in proportion to their size, consume more air, (indeed a couple of sparrows require as much air as a Ouinta pig. I’lants cannot live without air any more than can animals. Roth plants and animals obtain air in the same manner. In a rose tree air enters the sap through the flue skin covering all parts of the tree. Air is also contained in the water which is taken up by means of the roots. In the fl-h air enters the sap, the blood by being contained in the water which the fish foices over its gills ; remove the air from the water by honing, and the fish wiil surely die. Man breathes by the air entering the blood through the skin covering his body, but especially through that Hue continuation of the skm inside the body which we call the lungs. Even an egg requ res air, or the living principle within soon perishes, so we see the saell drilled with minute holes. I have heard of persons stopping up these holes by varnishing the egg, in this war preserving it in good condition for some time, for the pve-ence of air is necessary for decay, and thus

■ oaud up closely aud inseparably with life is decay or death, fur just as surely as in walking the sole of your boot wears, so does ibe flesh that moves the foot, and the nervous system that sets in action the flesh. Fortunately repair goes on in the foot as quickly as decay, and thus it becomes no smaller; let tl e r=pau- be in excess and the fool grows. Disorder the repairs of this our jbody, or let any part of it ho blocked up by the ■rubbish caused by the wear arid tear, and you |have disease; excessive disorder or excessive i blocking up stops the whole machine, and the i man U dead. j fTo be e/mtatesed- 1