Читать книгу The Horse's Mouth, Showing the age by the teeth - Mayhew Edward - Страница 4

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SHOWING THE AGE

BY

THE TEETH.

1. That the teeth of the horse denoted the age of the animal appears to have been a very ancient belief, which the experience of centuries seems in no degree to have weakened. As a general rule, applied within certain limitations, the impression is certainly well founded; for perhaps no development is more regular than the teeth of the horse, and no natural process so little exposed to the distortions of artifice. We are, nevertheless, not to expect that the animal carries about in its mouth a certificate of birth, written in characters so deep or legible that they cannot be obliterated or misinterpreted. The indications to be discovered by an inspection of the mouth of the horse, however, are so generally true, that in these dependence may be placed; although they are not so arbitrary or invariable, that upon them in every instance an absolute opinion can hastily be pronounced. He who would judge of the age by the teeth, must therefore be content to study and prepared to encounter difficulties. In proportion as he has done the one, and is fortified thereby to overcome the other, will be his success. There is no secret charm which will enable man to unravel Nature’s mysteries. Her ways are regular, but they are not uniform—her laws are fixed, but her acts cannot be measured by a system of rule or compass. The qualified judge alone will read the teeth correctly; but in proportion as the task is difficult, will be the candour and caution of him who fulfils it properly. He will make allowance where certain marks are indistinct or absent—he will not feel himself degraded by a confession of inability to speak with certainty when the signs are complex or confused—and above all, he will be cautious before he pronounces a final opinion, and gives it forth as a decision, against which there ought to be no appeal. The Veterinary Practitioner knows from repeated trials, tested by long experience, that the teeth of the horse are worthy of attention; he feels that their indications, scientifically interpreted, will seldom mislead; but he does not regard them with a reverence resembling that originating from an antiquated superstition, or look upon them as the exemplifications of a principle which admits of no exceptions.

2. In every case the evidence of the teeth is secondary to direct and substantiated testimony; for as there is no limit to possibility, so no man can be prepared to say what Nature may or may not do. In the absence, however, of positive and corroborated testimony, the teeth become the best evidence, and that on which reliance should be placed. When opposed to the indications of the mouth, the oath of a single individual, for obvious reasons, would be of no weight. A foal can hardly be born without many parties being cognizant of the fact—the colt cannot change its master without several persons being made aware of the transaction—and horses, for honest purposes, are not generally sold or bought in secret. Proof of the age can generally be adduced, if the parties interested think proper to seek it; or when it is not possible to adduce such proof, the teeth deserve more confidence than an uncorroborated assertion. An individual may be interested to mis-state, or may be mistaken in his belief; whereas the teeth, being natural growths, are removed from such suspicions.

3. Some of the causes which induce certain persons to doubt the possibility of the horse’s age being accurately told from the teeth, are not difficult to explain away. The Jockey Club has seen reason to declare, that all thorough-bred animals shall be born on the 1st of January, or if any should make their appearances at a later period, such shall be esteemed one year old when the 31st of December has expired. All blood horses have but one birth-day, nor do they in that respect differ from their brethren of the coarser breeds; only those of the last description are supposed to begin their existences upon the 1st of May. If a racer has seen six Januaries, it is said to be six years old; and if a nag had looked upon half a dozen Mays it would be pronounced to be of a similar age. These customs are convenient, as affording a point from which to date the age of an animal; but under such regulations, confusion will and does frequently arise. In a long number of years, a few months may be of little importance; but at the earlier period the difference of several weeks may, in the calculation of the age, be a serious matter. I will endeavour to show how far, in an extreme case, confusion may be created by the operation of these customs, and to prove, that he who should read the teeth correctly, would be unable to satisfactorily pronounce the accepted age of a colt. According to the received laws, a blood foal dropt on the 31st of December, and a foal not thorough-bred, born on the 30th of April, would each, the second day of life, complete the first year of its existence. Let it be supposed that a blood mare bore a foal in the latter end of December—the animal would be entered in the stud book according to the year of its birth, but for obvious reasons could never be put into training; it would be kept until another January arrived, when, although but one year and a few days of age, it could, in strict accordance with the established custom, be sold as a two-year-old; and the entry being in the stud book, of course the point would not be disputed. The colt is bought and taken into an ordinary stable, where all the horses not being thorough-bred advance a year when the 1st of May appears; and when that day dawns, the blood colt, not eighteen months of age, rising with the rest, is called three years off. Now in such a case, the man who judged by the teeth would be certain to be wrong; and if it is possible under any circumstances for truth to be discredited, we may imagine that many apparent mistakes would, on inquiry, be cleared up. The age of a horse is seldom correctly stated even in a court of law. Witnesses swear by the customs of men, and it never seems to occur to them that Nature has not yet given in her adherence to the codes by which their consciences are narcotized. Horses are born at all times and seasons. The regular breeder, it is true, takes care towards the observance of the regulations; but all who may think proper to have “a foal out of the old mare when she’s done up for work,” are by no means nice in that particular. Stallions are paraded for “service” in the autumn, and there are to be found men who will argue stoutly in favour of a “late get.”

4. The teeth more frequently contradict an arbitrary calculation than disagree with fact. The mouth declares only the positive age, reckoned from the actual day of birth, and I know of no evidence of a similar description which may be more confidently trusted. Occasional exceptions are to be found, and of these notice will be hereafter taken; such exceptions, however, are not sufficiently frequent to upset the rule, and were the testimony of the teeth to be rejected, I know of no other that could be substituted. We are therefore necessitated to retain the test, and consequently should know how to apply it. Almost every one within or about the stable pretends to be able to do this, but some even of those who have studied the subject are not capable of doing it correctly. The evidence is often true when the judgment is false, and in this circumstance, perhaps, lies the chief danger of the test. A knowledge of the teeth is by no means universal; but where that knowledge is profound, though the test may seldom disappoint, yet because it will occasionally do so, the indications of the mouth ought to be corroborated. To proceed summarily (as in the case of the Queen of Cyprus) upon an inspection of the teeth, is certainly not justifiable, since the mouth may possibly be eccentric, or the judgment pronounced upon it may be erroneous. The teeth in every horse case are of importance. The suggestions to which they give rise should not be disregarded; yet at the same time no opinion of a final kind should be based upon their showing. The utmost that the inspection of the teeth could warrant is a doubt, certainly a strong one, as to the reported age of the animal. That doubt would justify inquiry, and the teeth can substantiate no more than the right to inquire. Some may be disposed to think that such a right would not be worth possessing; but it must be remembered, that until the inquiry were ended, no decision as to the qualification of the animal could be arrived at. A valid doubt would have been created. Let the owner of the suspected horse dispel it, or the party who is interested to do so have time to seek the evidence which would convert it into certainty. The umpire, on the showing of the teeth, would be bound to withhold his judgment, not called upon to decide. Were such the rule, all fear of injustice would be guarded against; and as gentlemen connected with the turf cannot endure suspicion, and are not very patient of delay, those who were the owners of animals, the mouths of which presented any peculiarities, ought to notify the fact some days before the horses started. By forbearing to do so, gentlemen expose themselves to accusation. By examining the animal at the moment of starting, and founding a decision thereon, no good can be done, but injustice may be perpetrated; for supposing the suspected horse is pronounced to exhibit the tokens of the lawful age, the inspection of its mouth by a stranger may, by exciting its irritability, lose the race. At the same time, to permit an unqualified animal to start, would be unjust; and therefore the greater necessity for such a timely inspection as would allow of a preliminary investigation of the proofs that could be brought forward in contradiction of the teeth. These suggestions are made with the less hesitation, as the writer feels that were they adopted, few cases would spring out of them; for the mouths of racers are so regular in their development, that the age of this description of animal can with more certainty be pronounced than that of any other kind of horse.

5. For the security of the purchaser of a horse not connected with the turf, the teeth are a sufficient guard, and their indications, when properly understood, may be confidently acted upon. This opinion is put forth after a matured consideration of the subject, and probably there is no dealer who would dissent from the decision at which the author has arrived. The purchasers possibly may, on reflection, see less reason to be satisfied, because the teeth would, perhaps, in many instances, seem to favour the interest opposed to theirs. Let the matter, however, be deliberately weighed, and perhaps it may be found that neither party is likely to gain considerably, or to be seriously injured. In ordinary trade, the word of the seller is not much regarded; but in horse transactions, the assertion of the dealer is never received. One source of evidence is therefore discarded, and some other must be sought. Now, where horses are concerned, even the oaths of men appear to be of little force; “hard” swearing is expected in every business of that nature, and such expectation almost disqualifies all those persons to whose testimony the dealer could appeal. Let it be remembered that it is not the dealer who refuses to give evidence, or to adduce it; but the purchaser, who is prejudiced against accepting it. This act on the purchaser’s part limits the proof he might demand; for as attestation is rejected by him, not denied to him, he is by his conduct left without cause of complaint, and bound to seek the evidence which he will accept. Such evidence he looks for in the mouth of the animal, and is seldom deceived when capable of interpreting it. The teeth, in fact, are the only testimony that his caution leaves him to decide upon; and it will be hereafter shown, that even when the teeth are early in their development, the purchaser is not virtually wronged. All men, however, seek to arm themselves by suspicion, when dealing in horse-flesh; and the tricks that are played upon the teeth, rise immediately to the mind. Such tricks certainly are played, but they are assuredly more talked about than practised. There is a superstitious idea afloat, that breeders can make horses appear of any age they please, by torturing the mouths of the poor animals. The folly of such a belief will be exposed in another part of this work; it is sufficient for the present to state, that the credulity of the public in this matter has no foundation. A colt cannot be made by any barbarity to look like a horse; and an old horse cannot be forced to exhibit the mouth of a colt. That attempts are made to disguise the teeth, and that such attempts occasionally impose upon the buyer, is not denied; but all of such practices are shallow in the extreme, and so easily detected, that the person deceived by them is not an object of pity. If people will presume to judge before they have learnt to recognize, their temerity is more to be blamed than its consequence is to be commiserated. No one goes to buy a horse unwarned of the dangers that will surround him; and if in his conceit he rather prefers to hazard these than to seek protection, what right has he to murmur at a result which it needed no conjurer to foretell? Is there any market in the world where ignorance is secure from imposition? The world is not yet so honest that the affairs of the horse mart are a subject worthy of its special wonder; and it may be doubted if the principles which regulate the conduct of the horse dealer, are not those which influence the transactions of the most honourable traders. There are men of the highest character living by the sale of horses; and it is creditable to humanity, that after all of a certain class have been unscrupulously stigmatized and openly reproached, there may still among its members be found, beings preserving honour for the sake of itself alone. The liberal public, however, in its wisdom, has pronounced the character of the horse dealer; it has rejected his attestations, and refused to listen to the testimony of those with whom he has communication. The age of a horse is not taken from the mouth of its owner, but looked for in that of the animal. This mode of procedure is convenient—the record is at hand, the evidence brief, and the decision to which it leads is that to which the purchaser by choice appeals. The dealer stands by and knows that his voice is to be restrained. The teeth denote the age, and when the word of the owner is not to be accepted, there is no other evidence at hand. Were additional proof to be required, in some instances it could not be procured, and in the majority its production would be attended with an expense perhaps equal to the price of the horse which it concerned. The expence, the seller of course could not be expected to bear, and the buyer equally would resist its infliction. Nothing is more high priced than absolute proof of any kind; and there is always a further difficulty in the difference of opinion which prevails, as to what constitutes absolute proof. A cursory glance at the matter is enough to convince us, that the custom of inspecting the teeth of the horse to ascertain the age of the animal, is one which has had its origin in necessity. Experience has taught that the mouth of the horse affords the most satisfactory evidence, and the author’s investigations on this subject have convinced him that the public need require no better or more conclusive testimony. The reader, however, before he ventures to abide by his own interpretation of the signs which the horse’s teeth exhibit, must be content to study, and prepared to find the task somewhat difficult. All that can be done to render the subject plain and clear, the author will attempt.

6. The description of the teeth cannot be rendered pleasing; but as it is a necessary part of the subject, the reader must exert his patience, while the matter is briefly discussed. Teeth are anatomically classed with bones, which in many respects they resemble. A tooth is divided into two parts, or into crown and fang. The crown is that portion which projects above the gum into the mouth; therefore so much as can be seen while the animal lives, is the crown of the tooth. The fang, the end of which is called the root, is that part of the tooth which is hidden from view, and is inserted into the jaw. For the convenience of description, however, other portions of the tooth have received distinct names, and the neck and table are spoken of. The neck is that portion of the tooth which is immediately surrounded by the gum. The table is the upper surface, or the part which touches the corresponding tooth of the opposing jaw when the mouth is closed. Such is the division made, and it will hereafter be found to assist the description of the various changes which the teeth undergo.

7. The teeth are situated in the maxillary bones, in which certain osseous cups, like indentations or holes, called the alveolar cavities, are developed for their reception. Each tooth has its separate cavity, and however close the crowns may appear, nevertheless each fang is divided from those before and behind by bony plates. The alveolar cavity always corresponds to the fang. As the fang alters in form, or diminishes in length, so does the shape of the cavity simultaneously change; and should the tooth be removed, the space, no longer needed, is filled up; the alveolar cavity being obliterated by a growth of bony matter.

8. Teeth are organised, that is, they possess nerves, arteries, veins, and absorbents, or are endowed with those vessels needed to resist decay, and to promote nutrition. That a tooth possesses nerves, no one who has submitted to have these members filed by the dentist, or who has endured the tooth-ache, can for an instant doubt; and that they are even, in some degree, susceptible of external impressions, the sensation produced by certain acids seems to render probable. The growth they exhibit shows they are gifted with arteries and veins; and these vessels can be traced directly to and from, though not unto, their substance. The existence of absorbents some have doubted; but the removal by nature of the fangs of the temporary teeth, clearly testifies the presence of these vessels.

9. The horse possesses forty teeth, viz., twelve incisors, four tushes, and twenty-four molars. The incisors, sometimes called nippers, are those which, situated in front of the mouth, are seen when the lips are parted. They are the instruments, by means of which the animal bites its food, and are placed six in the upper, and six in the lower jaw. They are classed as pairs, being generally cut or developed after that fashion. The middle two, in both jaws, are called the centre incisors; the two most backward, on either side of the mouth, the corner incisors; and the teeth, by which the corners and centres are separated, the lateral incisors. Of the tushes, the two placed in the lower jaw are the most forward. These teeth, which are sometimes termed canines, and sometimes cuspidati, (from cuspis, a point,) are isolated, appearing in the space which divides the incisors from the molars. They are only fully developed in the male, the mare often being without any indication of them, and never displaying them in so prominent a degree as the horse. Their use is not very apparent, but they certainly would be employed in those combats to which stallions seem naturally predisposed, and would render the grasp, and the wound it could inflict, more severe. Because the mare is of a more pacific temperament, Nature seems to have denied to her a perfect tush, by the presence or absence of which, the sex is indicated by the mouth, and upon which castration appears to exercise no influence, since the gelding has as well-formed a tush as the perfect male. The molars are ranged in companies of six, one company on either side of the upper, and a like number similarly situated in the lower jaw. The molars are the instruments which enable the horse to grind down the fibrous and hard food upon which it subsists, and they are distinguished by their locality, as first, second, third, fourth, fifth, or sixth molar tooth of the near or off side in the upper or lower jaw; the first being that growing in front, or nearest to the incisors, and the sixth that placed most backward in the cavity of the mouth.

10. Three substances enter into the composition of the horse’s tooth. Each of these substances is distinct, and can be distinguished from either of the others. The names given to the various parts are—1, crusta petrosa, or hard crust; 2, enamel; and 3, ivory.

11. The crusta petrosa is the most externally situated, and when the tooth first appears in the mouth, it is entirely coated by this substance, having a somewhat dull and dark appearance, which is only lost when the hard crust is removed by attrition, and the enamel thereby exposed. In amount, the crusta petrosa is second to the ivory, being more in quantity than the enamel. In composition, it is characterized by containing a great amount of animal substance; and, in structure, it is peculiar for exhibiting, under the microscope, numerous corpuscles or cells, from which pores or minute tubes appear to radiate. Within the alveolar cavity, the crusta petrosa, which around the fang becomes of considerable thickness, is of a yellowish white colour; but where, in connexion with the crown of the tooth, it is exposed to the chemical action of the food and air, it presents a darker aspect and looks like an accumulation of tartar, for which indeed it has been mistaken. It fills up the infundibula of the molars of the upper jaw, and lines those of the incisors, being pierced by all the vessels which nourish the teeth. If a tooth be subjected to the action of dilute hydrochloric acid, the enamel will be removed, and the ivory and crusta petrosa be rendered separate and distinct.

12. The enamel of the horse’s tooth appears to be unorganized, and to contain no animal matter. Hydrochloric acid entirely dissolves it with a slight effervescence, and though a few and a very few threads remain, these rather seem to be connexions between the ivory and crusta petrosa, than component parts of the enamel itself. That the enamel is an unorganized substance, it may be essential to state, is asserted only of this body in the tooth of the horse; for the enamel of the cow’s tooth is of a different nature, since hydrochloric acid does not dissolve it, affect its whiteness, or destroy its form. The enamel is the least of the three components of the tooth; of a whitish semi-transparent shining aspect, it forms a thin crust to the ivory, lying immediately under the crusta petrosa, and extending nearly to the root.

13. The ivory forms the main bulk of the tooth, and though blood vessels can be traced to, but not within its substance, yet it presents numerous pores or minute canals, radiating from the centre to the circumference, which the mind naturally associates with nutrition. These pores cannot be traced to the cells or corpuscles of the crusta petrosa, though in works of high authority, drawings obviously indicating such a connexion, are presented; they are limited to the ivory, and terminate within it. What their exact use may be, is not known, but that they are of service, their presence is sufficient proof. Like the minute canals of bone, they probably convey a serous or colourless fluid, for the nutrition of the part in which they are developed.