The next step was that a poisonous substance may develop itself or settle in the wound, and especially in gunshot wounds—a substance which has nothing to do with powder or lead. Paré himself adopted this view. When he took part in the siege of Rouen many wounds sloughed and had a cadaverous smell, and on opening the bodies of those who died numerous collections of pus were found in different parts full of greenish ill-smelling ichor. Besiegers and besieged believed themselves to be wounded with poisoned bullets. Paré looked for the cause in a deterioration of the air by the large quantity of decomposing substances, and he appears to have assumed, as is done at this day, a direct action of the so-called deteriorated air upon the wound itself.
The evil influence of air vitiated by the products of decomposition, not upon wounds only, but upon the organism generally, has never been lost sight of by physicians since that time. That rotten straw, decomposing bodies of men and animals, surfaces saturated with excrement, and overcrowding of badly-ventilated hospitals give rise to infectious fevers and unhealthy state of wounds is not a result of modern observation only. That it was a question of the processes of fermentation which became communicated to the body by means of the exciters of fermentation contained in the air was a view frequently adopted. "To quote one only out of many; John Pringle, in his Observations on the Diseases of the Army, published in 1775, devotes a chapter especially to 'Diseases resulting from Bad Air,' and his forty-eight experiments on septic and antiseptic substances contain numerous hints at attempts resembling those made at the present day to determine the antiseptic power of certain things. No advance was made, however, beyond vague surmises concerning the nature of the exciters of putrefaction, and they were for the most part looked for amongst the volatile, ill-smelling products of decomposition, and were believed to be extremely subtle gaseous matters."6
6 German Clinical Lectures, Second Series (New Sydenham Soc., 1877), p. 67 et seq.
Ambrose Paré (1582) first taught that secondary abscesses in surgical cases, "which he had observed in the spleen, lungs, liver, and other viscera, were due to a changed condition of the fluids produced by some unknown alteration in the atmosphere and determining a purulent diathesis."7 The following quotations force the conclusion that in the early history of medicine there was supposed to be some important relation between wounds of the head and multiple abscesses. "Nicholas Massa (1553) mentions a case of abscess of the left lung, following an injury of the head."8 "Valsalva (1707) was induced by his own observation to say that the viscera of the thorax were sometimes affected in wounds of the head." "Desault (1794) considered abscesses of the liver to be a very frequent sequence of head injuries."9 The fact that wounds of the head were frequently followed by abscesses of the lungs, liver, and other organs probably led to the opinion expressed by Desault, Barthez, Brodie, W. Phillips, Copeland, and others, that the disease had its origin in a nervous agency.10 "Bertrandi and Audouille (1819) sought for a mechanical explanation of the occurrence of hepatic abscesses after head injuries and in cases of apoplexy." Morgagni (1740) somewhat obscurely hinted at the doctrine of the reabsorption of pus—a doctrine which was afterward elaborated by Quesnay in 1819. Morgagni, after quoting a great number of instances of wounds of the head followed by visceral abscesses, opposes the idea of a mechanical transportation of pus thither, and states that abscesses are not confined to the liver and that they may follow wounds and ulcers of other parts besides the head. He ascribes their formation to particles of pus (not always deposited in the form of pus) resulting from the softening and suppuration of small tubercles, which, having been mixed with the blood and disseminated, are arrested in some of the narrow passages, perhaps of the lymphatic glands, and by obstructing and irritating these, as happens in the production of venereal buboes, and by retaining the humors therein, distend them and give origin to the generation of a much more copious pus than what is carried thither; and by this means, he says, we may also conceive how it is that much more pus is frequently formed in the viscera and cavities of the bodies than a small wound could have produced.11
7 Braidwood on Pyæmia, p. 2 et seq.
8 Ibid., p. 2.
9 Ibid., p. 3.
10 Ibid., p. 10.
11 Ibid., p. 3 et seq.
Cheston (1766) believed that the translation of matter from one point to another was a frequent occurrence after amputations of the larger limbs. John Hunter (1793), and after him Velpeau, demonstrated the existence of pus in the blood. Hunter believed that the pus was derived from the interior of the inflamed veins. He described three forms of inflammation of these vessels—viz. adhesive, suppurative, and ulcerative. Pyæmia he considered to be an aggravated form of phlebitis. Arnott (1829) concluded from his observations—1, That death does not result from the extension of the inflammation of the veins to the heart; 2, that the dangerous consequences of phlebitis have no direct relation to the extent of the vein which is inflamed; and, 3, that the presence of pus in the veins, though the principal, is not the sole, cause of the secondary affection. He accordingly opposes the idea of Abernethy, Carmichael, and others that the constitutional affection is owing to the extension of the inflammation to the heart. The publication of Arnott's and Dance's treatises led to the general opinion being held in England and in France that phlebitis and purulent infection were identical affections, or, at least, that the latter was invariably caused by the former.12