The intermittent and intercurrent pulses are opposed to one another, there being a complete failure of a pulsation in the one case, and an accessory or superfluous one in the other. There cannot be a better proof of the imperfection in our modern systems of the pulse, than that there should be no mention in them of the intercurrent pulse.
The hectic pulse, it is well known, is small and dense. Alexander Trallian says, small and feeble. (xii, 4.)
The serrated is hard, quick, and unequal in its feel. Rhases says that it is principally observed in inflammations of the pleura and diaphragm. According to Actuarius, the pulse characteristic of inflammation is serrated and hard, more especially if seated in a tendinous part. (Meth. Med. i, 25.) Le Clerc renders it le pouls en manière de scie. (Hist. de la Méd. p. iii, l. iii, c. 3.) It appears to correspond with the pulse called harsh in the works of English writers on medicine.
Borden speaks of the terms formicans, myurus, and caprizans as having been justly banished from our modern nomenclatures. But it may be doubted whether it be from superior information or from ignorance that we have rejected these nice distinctions. Some of these terms were in use long before the time of Galen, (he mentions that Herophilus used the term dorcadissans,) and for more than a thousand years afterwards the characters of the pulse to which they were applied were acknowledged as real; and, on a matter depending solely upon experience and observation, the concurring suffrages of so many ages must be admitted to be entitled to some consideration. That many of the Greek and Arabian physicians were men of great learning and of much practical skill in medicine cannot admit of a doubt; and therefore their opinions ought not to be hastily rejected as visionary and unfounded. Galen, indeed, expresses in strong terms the difficulty which he found in defining accurately the states of the artery to which the terms we are treating of are applied, and warns the reader that such characters are to be detected only by a person well experienced in the art of feeling pulses, which he pronounces to be one not easily attained. (Synops. viii.) Alsaharavius insists strongly on the necessity of having a nice sense of touch, and that it be well cultivated in order to attain the tact of feeling pulses properly. Haly Abbas and Actuarius in like manner state the difficulty and importance of the art of feeling pulses. It is to be borne in mind that the ancients performed the operation of feeling the pulse more methodically than is now generally done, which may in part account for our having lost sight of some of the nicer shades of distinction which they recognized. It is worthy of remark, further, that the truly learned and experienced Prosper Alpinus recognized and described these characters of the pulse which we have been treating of. (De pr. Vit. et Morte ægrot.)
Whoever will consult Galen’s treatises on the pulse will find discussed in them many subtle questions which are now seldom thought of. For example, he enters into a disquisition whether or not we can perceive the systole of the artery. He informs us that Agathinus had denied and Herophilus affirmed the possibility of this. He, after having, as he says, examined the matter fully, agrees with the latter. (De Dignosc. Puls. i, 3.)
Psellus gives the characters of the pulses in not inelegant politic verses. A very clear and satisfactory description of them is given in the short treatise of Theophilus Protospatharius.
The causes which produce all these varieties of pulse, and the changes of the system which they indicate, are, upon the whole, pretty clearly explained by our author; and the reader who wishes to consult other abridgments of the doctrines of Galen, may find them in the works of Rhases, Haly Abbas, and Actuarius. We shall merely make a few more remarks upon some of the more obscure and least understood parts of the system.
Respecting the myuri, Galen states that they all indicate a prostration of the vital powers, but differing in degree, according to circumstances. When the pulse gradually becomes smaller, and in like manner recovers its magnitude gradually, and so on alternately, so as to form the recurrent myuri, it indicates an inferior degree of prostration; and, when the diminished state of pulsation continues permanent, a greater degree of oppression is indicated. In the former case the powers of the system seem able to struggle against the load, but in the latter they are completely overcome. This state is next in danger to that of complete asphyxia. These three are the worst kinds of pulse. The intermitting is said by him to be allied to these, being indicative of great danger, though inferior to that of those we have mentioned. Next to the intermitting is the intercurrent, which indicates that the powers of the system are strong, but oppressed, and contending against some great load. Galen was particularly apprehensive of the intermitting pulse, which he held to indicate that the system is struggling against some urgent cause. He remarks, however, that, when the pulse is otherwise strong and frequent, it indicates less danger than when it is weak and slow. But, upon the whole, he considered this kind of pulse so full of danger, that he affirms he had never known a person recover whose pulse intermitted during the interval of two pulsations. When the pulse intermits during the space of only one pulsation or a little more, he says he had often seen the patient recover. He also states that an intermitting pulse is less dangerous in old persons than in adults or children. Some, he says, affirm that they have seen cases of intermission which did not prove dangerous, but he believes that they had confounded rarity with intermission. The intermitting is to be distinguished from the rare by the length of the time of rest, and by the latter being often equable, whereas the former is always unequable. He says it is generally occasioned by frigidity of the heart. These doctrines may be traced through all the subsequent authorities, both Greek and Arabian, down to Actuarius.
Galen, Rhases, and Haly Abbas repeatedly inculcate that the undulatory pulse indicates an approaching crisis by a sweat. They describe it as being strong, full, soft, bounding, and unequable. According to Galen it is most commonly met with in lethargic affections, quotidian, marsh, and typhoid fevers. (De Præs. ii, 9.) It is also said to be common in sudden attacks of dropsy. (Ib.) In some instances, however, it is the precursor of some critical evacuation, such as that by the hemorrhoids, or by the bowels. (Synops. 22.) Actuarius particularly states that critical sweats are indicated by the undulatory pulse. (Meth. Med. ii, 2.)
The dicrotos is distinguished by a smaller pulsation suddenly succeeding to a larger one. Galen compares it to a hammer, which, when forcibly struck against the anvil, rebounds, and strikes it again. The artery in such cases is always strong and vibratory. Philaretus describes the pulsation as being hard, vehement, and rebounding. Galen says it can only occur when the powers of the system are strong, the artery hard, and the body oppressed with a redundance of humours. He repeatedly inculcates that it indicates an approaching crisis.