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dent:" for in the first example, a full degree of radical abruptness in the tonic'a' is not required.

It is upon the principle of the syllabic agency of the radical and vanish, that the passed time and perfect participle of some verbs ending in ed,' when contracted into one syllable by rejecting the tonic 'e, change d'into it,' as : snatched snatch't; passed pass't; stopp't; check’t. For if the e' be dropped, the 'd' which remains having a vocality, and possessing as a subtonic the power of a concrete movement, it must, when preceded by an abrupt or atonic element, as in the above instances, exhibit a radical and vanish, and consequently must make a syllable, in place of that made on “ed ;' which, by the proposition, was to be rejected. But if the abrupt atonic 'l is substituted ford,' that element may be retained without destroying the singleness of the syllabic impulse.

Those irregular verbs which, by contraction, have their present and past times and perfect participle alike, are generally found to end in it,' as: beat, hurt, let, left. The economy of utterance or the occasions of poetical measure, producing a contraction of the regular form of beat beated beated,' which we may suppose to have been the original structure of the verb, the operation of the radical and vanish in syllabication does not allow the contraction to be made by the mere elision of 'e.' For upon this elision, . beated,' can be changed to one syllable, as we have seen above, only by substituting the atonicót' for the subtonic •d,' as in beat't,'—and this differs so slightly from beat' that this single word would be used as the inflection of the verb, and as the participle. · I might still further apply the foregoing principles, in the explanation of many apparent anomalies in speech, which have hitherto passed without scrutiny or without satisfactory interpretation. But I have already exceeded my original intention, in planning the subject of this section; and must therefore leave other particulars, to the observation and reflection of the reader. Perhaps I do not exceed the bounds of reasonable anticipation, when I foresee his rising interest in this history of the voice. But all these things, and more too that I shall tell, may be made by him, to seem only like the preface to a full knowledge of this subject,-if he will adopt the mode of inquiry which has thus far assisted me :if he will become the spy upon nature, through his own watchfulness, and not draw too much from the precarious source of authority :-if he will turn from those discouraging prospects, presented by the result of every attempt to make knowledge out of notions; and by entering into sober communion with his own senses, lay himself open to the advising of those five ministers of knowledge, appointed by nature for his counseling in all truth.

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SECTION V.

Of the Causative Mechanism of the voice,-in relation to

its different Qualities.

A DESCRIPTION of the different sorts of sound of the human voice, without an exemplification by actual utterance, is al. ways insufficient and often unintelligible. With a view to facilitate instruction, it is desirable to discover the mechanical movements of the organs, and the mode of action of the air upon them ; that a reference to the conformations and changes of the organs and to the impulses of the air, may enable any one to have a precise perception of the nature of described sounds, by using the known physical means which produce them.

The result of physiological inquiry on this subject is not satisfactory. It has happened unfortunately that most physiologists have been public teachers, appointed to stations of influence, and directed by the rules of their office, to instruct without having the time or ability or disposition to investigate. Their condition has obliged them to compile without choice, to define and arrange without reflection, and to affect an originality which may have been forbidden by the frame of their minds, or the multiplicity of their duties. From these professorial instructors, the covered movements of the organs of speech, seem to cut off the means of observation ; and whilst they have feigned themselves under obligation to teach what they had never learned, they have endeavoured to elude the difficulty, by framing some of those works of fancy which the craft of mastership long ago devised, for satisfying the cravings of undiscerning youth. The puerile wishes of the scholar have been respectfully regarded by the teacher; and knowledge under his hands, has frequently been rather a picture of the pupil's anticipations, than the truth, and nothing but the truth of nature.

There are few confirmed opinions among writers, on the mechanism of the voice; and by the duties of philosophy, we are bound to acknowledge much ignorance on this subject. We know that the voice is made by the passage of air through the larynx and cavities of the mouth and nose. From experiments on the human larynx, and from observations upon the vocal functions of dogs, by exposing the organs in the living animal, it is inferred with great probability, that the production of voice is connected with the vibration of the ligaments of the glottis. We have no precise knowledge of the causes of Pitch; its formation having been by authors differently attributed to the contraction of the glottis,—the shortening of its chords, their altered degrees of tension,-the varying velocity of the current of air through the aperture of the glottis,—the rise and fall of the whole larynx and the consequent variation of length in the vocal avenues, between the glottis and the external limit of the mouth and of the nose,-and finally, to the influence of a union of two or more of these causes. Nor are we acquainted with the mechanisms which respectively produce those varieties of sound called the Natural voice, Whisper, and Falsette. Each of these varieties has received some theoretic explanation ; and their locality has, without much precision, been severally assigned to the chest, throat and head.

These discordant and fictional accounts have been in some measure the consequence of conceiting a resemblance, between the organs of the voice and common instruments of music: and whilst those fluctuations of opinion which never belong to truth, have represented the vocal mechanism to be like that of mouthed or reeded or stringed instruments, the spirit of these unfounded or still incomplete analogies has been carried to the outrage of all similitude, by comparing the track of the fauces, mouth and nose, to the body of a flute; and by ascribing a want of accuracy in intonation to an inequality of tension between what are called the strings of the glottis.' We are too much disposed to measure the resources of nature, by the limited inventions of art. The forms of matter, which jointly with the motion of air, may produce sound, must be innumerable; and there certainly is no great comprehensiveness of inquiry, in that view of the mechanism of the human voice which regards only the functions of those few forms that have received the names of musical instruments.'

The illustrations which these analogies are supposed to afford, are no more than resting places for the mind in the perplexed pursuit of truth. The physiologists of antiquity thought they explained the mysteries of the voice when they compared the trachea to a flute; and science reposed from the time of Galen, to that of Dodart and Ferrein in the eighteenth century, on the satisfaction produced by this fancy. The means of illustration have followed the fashion of instruments, and of late years the chords of the æolian harp and the reed of the hautboy, have furnished mechanical pictures of the organs of voice. One can not say positively, that a resemblance of the mechanism of the voice, to some known instrument of music, may not be proved hereafter ; but cautious reflection will guard us against surprise on a future discovery, that in most points, the functions of the two cases are totally dissimilar. Before the use of the balloon for the support and progression of men upon the air, no one ever imagined the possibility of his flight, through any other instrumentality than that of wings.

The history of the voice consists of some due experiment and observation, and of inferences from the principles of musical instruments applied without much precision to the human organs. We seem to have been so entirely convinced of the analogy between these cases, and have relied so implicitly on systems constructed upon it, that we have forgotten the importance of unbiased observation. The vanity of fancying knowledge completed, and despair in thinking it unattainable are equally adverse to the efforts of improvement. The pure and transcendant spirit of Baconian science, directs us by its productive rules, to record all the phenomena of the voice ; and requires us to know resemblances and differences, not to imagine them. There is no doing without the counseling of analogies, in investigating the processes of nature. With peculiar adaptation to a varied purpose, they are the happy instruments of genius, both for hewing out and for finishing truth : but they should never be confounded with the objects, which they are intended merely to shape and to decorate. In the present inquiry, it might be proper to take into consideration all the artificial instruments of sound; but when a strict use of the senses can not prove a similarity of function between them and the organs of voice, it can be no benefit to retain as parts of a science, those means which have been used in unsuccessful attempts to discover its truth.

When I speak of our ignorance of the mechanical causes of the different kinds of voice and of their pitch, I beg to be clearly understood. To know a thing as this phrase is applied in most of the subjects of human inquiry, is to have that opinion of its nature, which authority, analogical argument, and partial observation, prompted by various motives of vanity or interest may create. To know in natural philosophy, we must employ our senses and contrive experiments on the subject of inquiry ; and admit no belief of it which may not at any time be illustrated by demonstration. Physiology is too full of the first of these modes of logic : and no branch exhibits it more conspicuously than that of the mechanism of the human voice. One, from the analogy of musical strings, says that Pitch is produced by the varied tension of the chords of the glottis ; without satisfactorily showing in what manner the degrees of tension are correspondent to the degrees of pitch in the human voice. Another teaches that the vibration of these cords performs the same function as the reed of the hautboy ; without a further explanation of the mode in which this laryngeal reed effects all the degrees of intonation. Whilst a third ascribes the pitch of the falsette to the agency of the base of the tongue, the arch of the fauces, the soft palate and the uvula ; without satisfying the doubt, that these varied and flexible structures have individually or collectively any fixed relationship to the current of respiration, in the production of that pitch.

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