Page images

cularly the provostship of Trinity College, Cambridge, which was repeatedly offered him by archbishop Usher. He died in 1638. All his works have been collected into one volume folio. His Comments on the Apocalypse are by far the best of his writings, and his system in explaining that mysterious book has been followed by some of our greatest modern divines.

MEDEA, in fabulous history, a celebrated sorceress, daughter of Eetes, king of Colchis. She was the niece of Circe. When Jason came to Colchis in quest of the golden fleece, Medea became enamoured of him, and it was to her labours that the Argonauts owed their preservation. (See JASON and ARGONAUTE.) Medea had an interview with her lover in the temple of Hecate, where they bound themselves by the most solemn oaths, and promised eternal fidelity. No sooner had Jason overcome all the difficulties which Eetes had placed in his way than Medea embarked with the conquerors for Greece. To stop the pursuit of her father, she tore to pieces her brother Absyrtus, and left his mangled limbs in the way through which Eetes was to pass. When Jason reached Iolchos, the return of the Argonauts was universally celebrated; but Eson, the father of Jason, was unable to assist at the solemnity, on account of the infirmities of his age. Medea, at her husband's request, removed the weakness of Æson, and by the juice of certain herbs restored him to the vigour of youth. Her conduct, however, to the daughter of Pelias, and her refusal to bring Pelias to life after they boiled his flesh in a cauldron, greatly irritated the people of Iolchos, and Medea, with her husband, fled to Corinth, to avoid the resentment of an offended populace. Here they lived for ten years, but the love of Jason for Glauce, the king's daughter, soon interrupted their mutual harmony, and Medea was divorced. Medea revenged the infidelity of Jason by causing the death of Glauce, and the destruc. tion of her family. (See GLAUCE). This action was followed by another more atrocious. Medea killed two of her children in their father's presence, and, when he attempted to panish the barbarity, she fled through the air upon a chariot drawn by winged dragons. From Corinth Medea came to Athens, where she married king geus. From her connexion with Egeus, Medea had a son, who was called Medus. Soon after, when Theseus wished to make himself known to his father (see EGEUS), Medea, jealous of his fame, and fearful of his power, attempted to poison him at a feast which had been prepared for his entertainment. Her attempts, however, failed of success, and the sight of the sword which Theseus wore by his side convinced Egeus that the stranger against whose life he had so basely conspired was no less than his own son. The father and the son were reconciled, and Medea, to avoid the punishment which her wickedness deserved, fled, at length, from Athens, and come to Colchis, where, according to some, she was reconciled to Jason, who

had sought her in her native country, after her sudden departure from Corinth.

MEDE'OLA. Climbing African asparagus. In botany, a genus of the class hexandria, order trigynia. Calyxless; coral sixparted, revolute; berry superior, three-seeded. Three species: Virginia: Ethiopia: the Cape.

MEDIA, a celebrated country of Asia, bounded on the north by the Caspian sea, west hy Armenia, south by Persia, and east by Parthia and Hyrcania. It was originally called Aria till the age of Medus, the son of Medea, who gave it the name of Media. The Medes were warlike in the primitive ages of their power, and were remarkable for the homage they paid to their kings, who were styled king of kings. This title was afterwards adopted by their conquerors, the Persians, and it was still in use in the age of the Roman emperors.

MEDIA, in botany. See DODECATHEON. MEDIANA, the name of a vein or little vessel, made by the union of the cephalic and basilic, in the bend of the elbow.

MEDIANT, in music, the appellation given to the third above the key-note, because it divides the interval between the tonic and the dominant into two thirds. When the lower of these thirds is minor and the upper major, the key is minor; and when the lower third is major and the upper minor, the key is major.

MEDIASTINUM, in anatomy, a double membrane, formed by a duplicature of the pleura; serving to divide the thorax and the lungs into two parts, and to sustain the viscera, and prevent their falling from one side of the thorax to the other. See ANATOMY.

To ME'DIATE. v. n. (from medius, Latin.) 1. To interpose as an equal friend to both parties; to intercede (Rogers). 2. To be between two (Digby).

TO ME'DIATE. v. u. 1. To effect by mediation (Clarendon). 2. To limit by something in the middle (Holder).

MEDIATE. a. (mediat, French.) 1. Interposed; intervening (Prior). 2. Middle; between two extremes (Prior). 3. Acting as a mean: unusual (Wotton).

MEDIATELY. ad. (from mediate.) By a secondary cause (Raleigh).

MEDIATION. 8. (mediation, French.) 1. Interposition; intervention; agency be tween two parties, practised by a common friend (Bacon). 2. Agency interposed; intervenient power (South). 3. Intercession; entreaty for another.

MEDIATOR, a person that manages or transacts between two parties at variance in order to reconcile them. The word, in Scripture, is applied, 1. To Jesus Christ, who is the only intercessor and peace-maker between God and man; 1 Tim. ii. 5. 2. To Moses, who interposed between the Lord and his people, to declare unto them his word; Deut. v. 5. iii. 19.

MEDIATO'RIAL. MEDIATORY. a. (from mediator.) Belonging to a mediator.

MEDIATORSHIP. s. (from mediator.) The office of a mediator.

MEDIA/TRIX. s. A female mediator


MEDICA'GO, in botany, a genus of the class diadelphia, decandria. Legume compressed, spiral, forcing back the heel of the corol from the banner. Thirty-seven species, almost all natives of the south of Europe; four common to the pastures and sandy soils of our own country. They are thus subdivided: A. Legumes crescent-shaped, more or less twisted; comprising nine species, all denominated moon-trefoil.

B. Legumes spirally twisted, comprising the rest, and denominated medich. Of all these the only species particularly worthy of notice is M. sativa, lucerne. It pertains to the former division, and is specifically characterised by having its peduncles racemned; legumes sinooth, spirally twisted; stipules very entire; leaflets oblong, toothed. As a green fodder it has of late years been very generally recommended and very successfully cultivated by our graziers. MEDICAL. a. (medicus, Lat.) Physical; relating to the art of healing (Brown). MEDICALLY, ad. (from medical.) Physically; medicinally (Brown).

MEDICAMENT. 8. (medicamentum, Lat.) Any thing used in healing; generally topical applications (Hammond).

MEDICAMENTAL. a. (from medicament.) Relating to medicine, internal or topical.

MEDICAMENTALLY. ad. After the manner of medicine (Brown).

To MEDICATE. v. a. (medico, Lat.) To tincture or impregnate with any thing medicinal (Arbuthnot).

MEDICATION. s. (from medicate.) 1. The act of tincturing or impregnating with medicinal ingredients (Bacon). 2. The use of physic (Brown).

in a

the substances employed in the art of healing, and to the article PHARMACY for the mode of compounding them, and their respective results state of combination. Thus limited, we shall consider the subject of medicine under the following heads: its History; its Theory; its Scope (usually called Nosology); and its Pracderably avails himself of an article upon the same tice and in so doing the present writer consisubject, which, by particular request, he drew up two or three years ago for another highly respectable work of a similar kind; to which, however, he will make two or three important additions, so as to render it as complete as the narrow scope to which we are necessarily confined will allow us. PART I.

History of Medicine.

The commencement of the medical profession, whether regarded as an art or a science, or both, is lost in the darkness of the earliest ages. The diately from their gods; and even among the fabulous history of the ancients derives it immemoderns, some writers of established reputation are of opinion that it may justly be considered as of divine origin: but without adopting any supposition, of which no probable evidence can be given, we may conclude, that mankind were naturally led to it from casual observations on the diseases to which they found themselves subjected; and that therefore, in one sense at least, it is as ancient as the human race; but at what period it began to be practised as an art, by particular individuals following it as a profession, is not known. The most ancient physicians we read of were those who embalmed the patriarch Jacob by order of his son Joseph. The sacred writer styles these physicians servants to Jos pb, whence we may be assured that they were not priests, as the first physicians are generally sup posed to have been; for in that age we know the Egyptian priests were in such high favour, that they retained their liberty, when, through a public calamity, all the rest of the people were made slaves to the prince. It is not probable, therefore, that, among the Egyptians, religion and medicine were originally conjoined; and if

MEDICINABLE.a.(medicinalis,Latin.) we suppose the Jews not to have invented the

Having the power of physic (Baron).

MEDICINAL. a. (medicinalis, Latin.) 1. Having the power of healing; having phy sical virtue (Milton). 2. Belonging to physic (Butler).

MEDICINALLY. ad. Physically (Dry


MEDICINE. (medicina, Lat. of uncertain derivation; perhaps from pudor, pendopez, cura, consilium ; curam gerere, consulere ; though this root was seldom or never, among the Greeks, applied to the study or cure of diseases, but generally ban or revw, the latter of which has never been anglicised, but from the former of which we obtain the word therapeutics.) The art or science of healing. In this extensive and general sense it includes the materia medica, or substances employed in medicine; pharmacy, or the mode of compounding them; and praxis, or the phænomena of diseases and practice of medicine. In a more limited, and perhaps a more correet sense, however, the term is confined to the last division; and in this sense alone we shall understand it in the present instance, referring the reader to the article MATERIA MEDICA for

art, but received it from some other nation, it is were their physicians as those of Egypt. That as little probable that the priests of that nation the Jewish physicians were absolutely distinct from their priests, is very certain. Yet as the Jews resided for such a long time in Egypt, it is probable they would retain many of the Egyptian customs, from which it would be very diffi. cult to free them. We read, however, that when king Asa was diseased in his feet, he sought not to the Lord, but to the physicians. Hence we may conclude, that among the Jews the medicinal art was looked upon as a mere human invention; and it was thought that the Deity never cured diseases by making people acquainted with the virtues of this or that herb, but only by his miraculous power. That the same opinion prevailed among the heathens, who were neighbours to the Jews, is also probable from what we read of Ahaziah king of Judah, who having sent messengers to inquire of Baa'zebub, god of Ekron, concerning his disease, he did not desire any remedy from him or his priests, but simply to know whether he should recover or not. What seems most probable on this subject therefore is, that religion and medicine came to

be mixed together only in consequence of that degeneracy into ignorance and superstition which took place among all nations. The Egyptians, we know, came at last to be sunk in the most ridiculous and absurd superstition; and then, indeed, it is not wonderful to find their priests commencing physicians, and mingling charms, incantations, &c. with their remedies. That this was the case, though long after the days of Joseph, we are very certain; and indeed it seems as natural for ignorance and barbarism to combine religion with physic, as it is for a civilized and enlightened people to keep them separate. Hence we see, that among all modern barbarians, their priests or conjurors are their only physicians.

We are so little acquainted with the state of physic among the Egyptians, that it is needless to say much concerning them. They attributed the invention of medicine, as they did also that of many other arts, to Thoth, the Hermes or Mercury of the Greeks. He is said to have written many things in hieroglyphic characters upon certain pillars, in order to perpetuate his knowledge, and render it useful to others. These were transcribed by Agathodemon, or the second Mercury, the father of Tat, who is said to have composed books of them, that were kept in the most sacred places of the Egyptian temples. The existence of such a person, however, is very dubious; and many of the books ascribed to him were accounted forgeries as long ago as the days of Galen. There is also great reason to suspect, that those books were written many ages after Hermes, and when physic had made considerable advances. Many of the books attributed to him are trifling and ridiculous; and though sometimes he is allowed to have all the honours of inventing the art, he is, on other occasions, obliged to share it with Osiris, Isis, and Apis, or Serapis. After all, the Egyptian physic appears to have been little else than a collection of absurd superstitions. Origen informs us, that they believed there were thirty-six demons or gods of the air, who divided the human body among them; that they had names for all of them; and that by invoking them according to the part affected, the patient was cured. Of natural medicine we hear of none recommended by the father of Egyptian physic, except the herb moly, which he gave to Ulysses, in order to secure him from the enchantments of Circe; and the herb mercury, of which be first discovered the use. His successors made use of venesection, cathartics, emetics, and clysters. There is no proof, however, that this practice was established by Hermes: on the contrary, the Egyptians themselves pretended, that the first hint of those remedies was taken from some observations on brute animals. Venesection was taught them by the hippopotamus, which is said to perform this operation upon itself. On those occasions, he comes out of the river, and strikes his leg against a sharp-pointed reed. As he takes care to direct the stroke against a vein, the consequence must be a considerable effusion of blood; and this being suffered to run as long as the creature thinks proper, he at last stops up the orifice with mud. The hint of clysters was taken from the ibis, a bird which is said to give itself clysters with its bill, &c. They used venesection, however, but very little, probably on account of the warmth of the climate; and the exhibition of the remedies above mentioned, joined with abstinence, formed most of their practice. The Greeks too had several persons

to whom they attributed the invention of phy
sic, particularly Prometheus, Apollo or Pæan,
and sculapius; which last was the most cele-
brated of any. But here we must observe, that
as the Greeks were a very warlike people, their
physic seems to be little else than what is now
called surgery, or the cure of wounds, fractures,
&c. Hence Esculapius, and his pupils Chiron,
Machaon, and Podalirius, are celebrated by Ho-
mer only for their skill in curing these, without
any mention of their attempting the cures of in-
ternal diseases. We are not, however, to sup-
pose that they confined themselves entirely to
surgery. They no doubt would occasionally
prescribe for internal disorders; but as they
were most frequently conversant with wounds,
we may naturally suppose the greatest part of
their skill to have consisted in knowing how to
cure these. If we may believe the poets, indeed,
the knowledge of medicine seems to have been
very generally diffused. Almost all the heroes
of antiquity are reported to have been physi-
cians as well as warriors. Most of them were
taught physic by the centaur Chiron. From
him Hercules received instructions in the medi-
cinal art, in which he is said to have been no
less expert than in feats of arms. Several plants
were called by his name; from whence some
think it probable that he found out their vir-
tues, though others are of opinion that they bore
the name of this renowned hero on account of
their great efficacy in removing diseases. Aris-
tæus king of Arcadia was also one of Chiron's
scholars, and supposed to have discovered the
use of the drug called silphium, by some thought
to be asafoetida. Theseus, Telamon, Jason, Pe-
leus, and his son Achilles, were all renowned for
their knowledge in the art of physic; the last is
said to have discovered the use of verdegris in
cleansing foul ulcers. All of them, however,
seem to have been inferior in knowledge to Pa-
lamedes, who hindered the plague from coming
into the Grecian camp after it had ravaged most
of the cities of Hellespont, and even Troy itself.
His method was to confine his soldiers to a spare
diet, and oblige them to use much exercise. The
practice of these ancient Greek physicians, not-
withstanding the praises bestowed upon them by
their poets, seems to have been very limited,
and in some cases even pernicious. All the ex-
ternal remedies applied to Homer's wounded
heroes were fomentations; while, inwardly, their
physicians gave them wine, sometimes mingled
with cheese scraped down. A great deal of their
physic also consisted in charms, incantations,
amulets, &c. of which, as they are common to
all superstitious and ignorant nations, it is su-
perfluous to take any farther notice.
In this
way the art of medicine continued among the
Greeks for many ages. As its first professors
knew nothing of the animal economy, and as lit-
tle of the theory of diseases, it is plain, that
whatever they did must have been in conse-
quence of mere random trials, or empiricism, in
the most strict and proper sense of the word.
Indeed, it is evidently impossible that this, or al-
most any other art, could originate from any
other source than trials of this kind. Accord-
ly, we find that some ancient nations were
accustomed to expose their sick in temples, and
by the sides of highways, that they might re-
ceive the advice of every one who passed. Among
the Greeks, however, Esculapius was reckoned
the most eminent practitioner of his time, and

his name continued to be revered after his death. He was ranked amongst the gods; and the principal knowledge of the medicinal art remained with his family to the time of Hippocrates, who reckoned himself the seventeenth in a lineal descent from Esculapius, and who was truly the first who treated of medicine in a regular and rational manner.

Hippocrates, who is supposed to have lived four hundred years before the birth of Christ, is the most ancient author whose writings have descended to the present day: and he is hence justly regarded as the father of medicine. In this period, and indeed till a century or two ago, the distinct branches of medicine and surgery were studied and practised by the same person : Hippocrates, therefore, has been universally regarded as having contributed equally to our physiological and anatomical knowledge of the human frame, and the few anecdotes relating to him for which we can find room have been already communicated to the reader under the article Anatomy. We shall here therefore only add those opinions of the Coan sage which more immediately apply to the science of general therapeutics, and which are most entitled to general attention.

diseases which are hereditary, or born with us, and those which are contracted afterwards; and likewise between those of a kindly, and such as are of a malignant nature, the former of which are easily and frequently cured, but the latter give the physicians a great deal of trouble, and are seldom overcome by all their care.

A foundation for the theory and practice of medicine being thus laid, the science was pursued with great avidity by Praxagoras, who nevertheless ventured, in some respect, to oppose the practice of Hippocrates, and by Erasistratus and Herophilus, of whom the last, as a disciple of Praxagoras, inclined rather to the Praxagorean than the Hippocratic school. Erasistratus, how. ever, acquired a higher fame, though a more steady adherent to the older and Hippocratic doctrines, and to him we are indebted for the first regular indications of the pulse. About this period the profession of medicine began to be divided into the three branches of dietetic, pharmaceutic, and chirurgic; or those who pretended to cure by regimen alone, disregarding and even despising pharmacy; those who undertook to cure chiefly by pharmaceutic preparations, (of which number was Erasistratus himself); and those who devoted their whole time and attention to the chirurgical department of the medical art.

The next division of medical practitioners was into that of dogmatists and empyrics; the latter having commenced with Serapion, of Alexandria, about the year 287 before Christ, who, according to Galen, retained the mode of practice of Hippocrates, but pretended to despise his mode of reasoning. In reality, the sect to which Serapion belonged, and of which if not the founder, he was a very zealous supporter in its earliest infancy, depended upon their own personal experience alone, whether progressive or fortui


On the contrary, the dogmatists affirmed, that there is a necessity for knowing the latent as well as the evident causes of diseases, and that physicians ought to understand the natural actions and functions of the human body, and consequently its internal organs.

As far as Hippocrates attempts to explain the causes of disease, he refers much to the humours of the body, particularly to the blood and the bile. He treats also of the effects of sleep, watchings, exercise, and rest; and all the benefit or mischief we may receive from them. Of all the causes of diseases, however, mentioned by Hippocrates, the most general are diet and air. On the subject of diet he has composed several books, and in the choice of this he was exactly careful; and the more so, as his practice turned almost wholly upon it. He also considered the air very much; he examined what winds blew ordinarily or extraordinarily; he considered the ir regularity of the seasons, the rising and setting of the stars, or the time of certain constellations; also the time of the solstices, and of the equinoxes: those days, in his opinion, producing great alterations in certain distempers. He does not, The physicians of chief fame who flourished however, pretend to explain how, from these subsequently to this division were Asclepiades, causes, that variety of diseases arises which is who opposed the Hippocratic theory of natural daily to be observed. All that can be gathered power and sympathy or attraction, by engraftfrom him with regard to this is, that the differ- ing upon medicine the physical principles of the ent causes above mentioned, when applied to Epicurean philosophy; Themison, the founder of the different parts of the body, produce a great the methodic sect, whose doctrines evinced equal variety of disorders; some of these he accounted hostility to the dogmatists and empyrics, and dimortal, others dangerous, and the rest easily vided diseases into the two classes of hypertonic curable, according to the cause from whence they and atonic, a division, which, in various modifispring, and the parts on which they fall In cations, has descended to the present day; Thessa several places also he distinguishes diseases, from lus, contemporary with Nero, a man of some the time of their duration, into acute, or short, merit, but of inordinate vanity; and Celsus, deand chronical, or long; he likewise distinguishes servedly denominated the Latin Hippocrates, diseases by the particular places where they pre- whose work is equally valuable for the purity of vail, whether ordinary or extraordinary: the its language, and the knowledge it communicates first, that is, those that are frequent and familiar of the state of medicine at the time he wrote. to certain places, he called endemic diseases; and the latter, which ravaged extraordinarily sometimes in one place, sometimes in another, which seized great numbers at certain times, he called epidemic, that is, popular dis ases; and of this kind the most terrible is the plague: be likewise mentions a third kind, the opposite of the former; and these he calls sporadic, or straggling diseases these last include all the different so.ts of distempers which invade any one season,

which are sometimes of one sort, and sometimes of another. He distinguished between those

About the year after Christ 131, in the reign of Adrian, appeared the celcbrated Galen, whose rame makes so conspicuous an appearance in the history of physic. Practitioners were at this time divided into the three sections of methodists, dogmatists, and empyrics; Galen inclined to the second party, but with a true eclectic spirit undertook to combine with its doctrine whatever existed of real worth in the two adverse systeins, and hence to reform and give a finish to the science of medicine, beyond what it had ever pos sessed b.fore. For the most part, he was a fol

lower of Hippocrates, whose name he revered and whose opinions he commented upon, asserting in the course of his comments, that he had never been thoroughly understood before. Like Hippocrates, he denominated the vital principle nature; like him, he admitted the existence of four distinct humours, from the predominancy or deficiency or disproportion of which originate the different temperaments of the animal frame, and the varieties in the different diseases to which it is subject: these humours are the blood, phlegm, yellow and black bile. He likewise established three distinct kinds of auras, gasses or spirits, a natural, a vital, and an animal, which he regarded as so many instruments to distinct faculties; referring the seat and action of the first chiefly to the liver, of the second to the heart, of the third to the brain. His authority, in spite of all the fancies which are interwoven into his system, continued to prevail til the overthrow of the Roman empire, and learning and the arts were transferred to the eastern empire, under the auspices of which, however, the science of medicine does not appear to have made any progress; the Saracenic physicians totally neglecting the study of anatomy, and every other auxiliary pursuit, and merely adding to the materia medica a variety of plants, whose names we now seldom hear of, and whose pharmaceutic virtues have long been despised and forgotten.

From the period at which we are now arrived till the commencement of the sixteenth century, the history of medicine furnishes no particulars of interest. It was this epoch that gave birth to Paracelsus, who having plunged deeply into the science of alchemy, if such a term as science be not prostituted by an application to such a subject, proscribing by one broad sweep all the reasonings of the ancient authors, endeavoured to explain all the facts and doctrines of medicine upon the principles of the fashionable pursuit of the day.

It was in 1628 that medicine acquired a knowledge of the momentous fact of the circulation of the blood, through the indefatigable labours of Dr. W. Harvey, who nevertheless had to struggle for years against a double torrent of nearly equal violence, before the jealousies and prejudices of the profession were completely mastered: some denying the fact altogether, and others contending that it was a point that had been ascertained for ages, and consequently that he was by no means entitled to the honour of the discovery. The establishment of this important fact, however, did not, even for a long period after its general admission, produce all the advantages, which might have been expected from it. For the physiologists of the day, in reasoning upon the powers by which this phoenomenon, as well as various others of the animal frame, was accomplished, unfortunately took hold of the mechanical philosophy as their guide; and every function was immediately attempted to be explained by the laws of projectiles, till the system at length destroyed itsel, by the absurdity of the extent to which it was pushed.

Boerhaave, at this period, led the way to an admirable reformation, both of principle and practice; and by uniting the doctrines of Hippocrates with the philosophy of the times, framed a theory of medicine, upon the supposition of acrimony, lentor, and other changes in the circulating fluids. Contemporary with Boerhaave were Hoffman and Stahl, both of whom deviatVOL. VII.

ing from the theory of Boerhaave, the first laid the foundation of the spasmodic hypothesis, by resolving the origin of all diseases into an universal atomy, or an universal spasm in the primary moving powers of the system: and the second into the action of certain noxious agents, controuled, however, by the internal existence of a rational soul, that directs the entire economy. The humoral pathology nevertheless continued to prevail, till, under the auspices of Dr. Cullen, the theories of Hofiman and Stahl were united into one common and ingenious system: a system which still holds its ground, though it has been since controverted by the sensorial hypothesis of Dr. Brown and Dr. Darwin, NONIAN and DARWINIAN SYSTEMS.


Theory of Medicine.


Health is a system of harmony; and several of the older theories were founded upon this idea alone. A morbid affection in one organ, or set of vessels, is almost sure to produce a morbid affection in another; and a morbid secretion of one kind is generally succeeded by a morbid secretion of a second, a third, and even a fourth. The head cannot suffer without affecting the stomach; nor the stomach without affecting the skin; nor the skin without affecting the kidneys. The blood vessels influence the nerves, the nerves the secernents, or vice versa. The study of medicine therefore necessarily implies, as its first or preliminary pursuit, a general study of the animal frame, in its fluids and solids, its structure, its functions, and its habits; and in this prelimi nary pursuit consists that part of medicine which is usually denominated its theory.

Animal Fluids and Solids.

Fluids. These may be divided into, 1. The blood. 2. Those formed during digestion, before

the food is converted into blood. 3. The secreted fluids.

The blood. This consists of serum, coagulable lymph, red part, superfluous water, and extraneous substances introduced.

The serum, coagulable lymph, and superfluous water, are diffused through one another, and the red part is mechanically mixed with them. Some of the extraneous substances are also mechanically mixed with them, and some diffused through them.

The serum is fluid in any degree of heat be tween 30 and 160 of Fahrenheit's thermometer. In a less heat it freezes, in a greater it coagulates, It consists chemically of a coagulable matter, and water in which common sal ammoniac, and phosphoric ammoniac, and generally common salt, and frequently saleuites, and fixed ammoniac, are dissolved; but it is a question whether the water chemically combined in the serum be also united with those neutral salts, or whether the serum, and the solution of these, are only diffused through one another. It is probably in itself colourless and inodorous; but it receives a yellowish or brownish hue from the putrescent mucilage of the blood, and acquires a smell from the essential oil. If it contained no neutral salts, it would be insipid, and incapable of stimulating. The superfluous water may be separated from it by filtration in the body, but that which is chemically combined with the other parts cannot. All the water may be evaporated from it by a less heat than 140 degrees of Fahrenheit's


« PreviousContinue »