SECT. LXV.—DIAGNOSIS OF THE TEMPERAMENTS OF THE LUNGS.
Not only does the stomach render us thirsty and otherwise, and excite a desire of warm and cold drink, but also the thoracic viscera, namely, the heart and lungs, and likewise the liver. And drinking does not straightway allay the desire, but a small quantity of cold drink will rather allay the thirst than a great quantity of warm. Persons so affected are refreshed by inhaling cold air, which has no effect in alleviating the thirst of the stomach. Thus, also, those who are contrariwise affected, suffer sensibly from breathing cold air; this is the strongest mark of coldness of the lungs; but they also hawk up phlegm, and expectorate it with coughing. Dryness of the lungs is marked by freedom from excrementitious discharges and from phlegm; and humidity, by being excrementitious, and rendering the voice dull and hoarse; and the recrementitious discharge is also very great when they attempt to speak in a louder or sharper tone.
Commentary. The ancients were of opinion, that the lungs are an accessory organ, made to administer to the heart. “It is the heart,” says Aretæus, “which imparts to the lungs the desire of drawing in cold air.” And in like manner, Theophilus holds that the other organs of respiration were made for the sake of the heart, in order that its innate heat may be cooled, increased, and nourished. (De Fabrica Hominis, p. 89, ed. Greenhill.) The physiologists differed respecting the uses of respiration. Thus, according to Galen, the famous Asclepiades held that it is for the generation of the soul itself, breath and life being thus considered to be identical; Philistion, Diocles, and Aristotle, for the ventilation of the innate heat; Hippocrates for its nutrition and refrigeration; and Erasistratus for the filling of the arteries with spirits. All these opinions are discussed and commented upon by Galen, who determines the purposes of respiration to be twofold: first, to preserve the animal heat; and second, to evacuate the fuliginous portion of the blood. He was aware of the analogy between respiration and combustion, and comes to the conclusion that they are processes of a similar nature: he accordingly compares the lungs to a lamp, the heart to its wick, the blood to the oil, and the animal heat to the flame. (Galen, de usu Respir.) Aristotle gives the name of pneuma to the vital heat of animals, and ascribes the source and maintenance of it to the double functions of respiration and digestion. (De Pneumate.) See further, [Third Book, s. 27].
The following extract from Alexander Aphrodisiensis will explain the opinions entertained by physicians and savans of a later age: “Wherefore there is a natural tepidity, the same I mean as the innate heat, whence springs the origin of the animal, its nature; for it is congenital with the animal, and therefore is called natural, being in the main the instrument of the soul’s powers.” (De Feb. viii.)
The following extract from Haly will show that the opinions of the Arabians on this subject did not differ from those of their Grecian masters, and more especially of Galen: “Respiration is necessary, for the sake of the heart, which is the fountain, and, as it were, the focus of vital heat, whence it is diffused over the rest of the body. It requires some aerial substance to ventilate the heat and ebullition of the heart, and in order to evacuate the fuliginous vapours which are found in it.” (Theor. iii.)
SECT. LXVI.—THE MARKS OF THE TEMPERAMENTS OF THE HEART.
These are the marks of an unusually warm heart: largeness of respiration, quickness and density of pulse, boldness and maniacal ferocity, the chest is covered with hair, particularly the breast, and usually the parts of the hypochondriac regions adjoining to it; and the whole body is hot, unless the liver powerfully antagonise. And capacity of chest is also a mark of heat, unless the brain in that case antagonise. But an unusually cold heart has the pulse smaller than moderate, and such persons are timid and spiritless, more especially if there be no hairs on the breast. Dryness of the heart renders the pulse hard, and the passions ungovernable, fierce, and difficult to quell; and, for the most part, the whole body is drier than usual, unless the parts about the liver antagonise. These are the marks of a more humid temperament: a soft pulse, a disposition easily roused to anger, and easily pacified, and the whole body more humid than common, unless antagonised by the parts about the liver. When the temperament is both hotter and drier, the pulse is large, hard, and quick and dense; and the respirations large, quick, and dense. And of all others such persons have the most hair upon the breast and præcordia; they are prone to action, given to anger, fierce and tyrannical in their dispositions; for they are both passionate and implacable. But, if humidity prevails with heat, such persons are less covered with hair than the afore-mentioned; they are prompt to action, their disposition is not fierce, but only prone to anger; their pulse is large, soft, quick, and dense. But when the temperament is more humid and cold than common, the pulse is soft, the disposition spiritless, timid and sluggish; they have no hair on the breast, and neither indulge in lasting resentment, nor are prone to anger. A cold and dry heart renders the pulse harder and small. Of all others, such persons are least given to anger, but when provoked they retain their resentment. They are also particularly distinguished by having no hair on the breast.
Commentary. In the ancient system of physiology, the heart was considered as the seat of the Vital powers, its office being the preservation of the innate heat of the body. The philosopher, Aristotle, had pointed out the connexion between heat and vitality, and had taught that the heart, as being the centre of heat, is the prime organ in the animal frame. Hence, as his commentator, Averrhoes, remarks, it is the primum movens et ultimum moriens. Galen, however, maintained with Hippocrates, that the animal frame is a circle, having neither beginning nor end, and that, consequently, it has no prime organ. He taught that the brain does not, properly speaking, derive its powers from the heart, nor the heart from the brain; but that these organs are mutually dependent upon one another, the heart being indebted to the brain for supplying the parts concerned in respiration with muscular energy, and the brain being indebted to the heart for its vital heat, without which it could not continue to be the vehicle of sensibility and motion. (De Placitis Hippocrat. et Platon. pluries.) We have mentioned in [the preceding Section], that the ancient physiologists looked upon respiration as being a process similar to combustion. See Galen (de Usu Respirationis), Alexander Aphrodisiensis (Probl. i, 16.)
The heart, then, was supposed to convey heat to all parts of the body, by means of the animal spirits incorporated with the blood in the arteries. Respecting the contents of the arteries, two hypotheses divided the ancient schools of medicine. The first was that of the celebrated Erasistratus, who maintained, that the arteries do not contain a fluid, but merely certain airs or vapours. The other hypothesis was that of Galen, who keenly attacked this, as he did most of the tenets of Erasistratus, and endeavoured to prove, by experiment, observation, and reasoning, that the contents of the arteries is blood, mixed, indeed, with a certain proportion of heat and airs, but in every respect a fluid, little different from that contained in the veins. It was also part of his system, that the right cavity of the heart attracts blood from the liver, and conveys it to the left, from which it is diffused all over the body by the arteries. He taught that, at every systole of the arteries, a certain portion of their contents is discharged at their extremities, namely, by the exhalents and secretory vessels; and that at every diastole a corresponding supply is attracted from the heart. He decidedly inculcates, in opposition to Asclepiades, that it is the expansion or diastole of the artery which occasions the influx of the blood, and not the influx of the blood which occasions the expansion of the artery; or, in other words, that the systole is the function of the heart, and the diastole its return to its natural state. (De Diff. Puls. iv, 10.) Though he demonstrated the anastomosis of arteries and veins, he nowhere hints his belief, that the contents of the former pass into the latter, to be conveyed back to the heart, and from it to be again diffused over the body. In a word, his system appears to have been nearly, or altogether, the same as that which was afterwards taught by the unfortunate Servetus.
It is clear, therefore, that Galen had made a very near approach to the Harveian theory of the circulation; indeed, Harvey himself candidly admits this. It will be perceived, from what we have stated, that the grand point of difference between Galen and Harvey, and that upon which the theory of the latter mainly rests, is the question whether or not at every systole of the left ventricle more blood be thrown out than is expended on exhalation, secretion, and nutrition. Upon this point Galen held the negative, Harvey, as we all know, the affirmative.