Sepsis, Asepsis, and Antisepsis. The Germ-theory of Disease. Gay-Lussac's Researches. Schwann. Tyndall. Pasteur. Davaine. Lord Lister and his Epoch-making Revolution in Surgical Methods. Modifications of his Earlier Technique without Change in Underlying Principles, which Still Remain Unshaken. Changes Effected in Consequence. Comparison of Old and Modern Statistics.
Modern surgery, and, in no small degree, modern treatment of all disease, have been so completely modified from previous methods by the introduction of the so-called antiseptic system that it seems to be only right to devote some time in such a work as this to a résumé of the history of the doctrines and experiments which have led to the perfection, as it would seem, of modern methods.
The adjective "septic" comes from the Greek word "sepsis," which is often transferred to the English, and which means "putrefaction," or that which is putrid, or undergoing decomposition. From this word are formed two others,—namely, "aseptic" and "antiseptic,"—the one implying the exclusion of all causes of putrefaction and complete freedom from it, the other referring to methods employed to antidote the effect or counteract the influence of the agencies which produce sepsis or destroy them while still within the living body. By general usage the term "antiseptic" has been construed as the more comprehensive; hence, the modern method is usually spoken of as "antiseptic surgery," and hence the title above: "The History of Antisepsis."
The principle underlying the resort to antiseptic methods is summed up in the expression, now so generally received,—the "germ-theory" of disease. It refers, in general, to the so-called zymotic, or infectious, diseases, whose manifestations are protean, which are all communicable by one means or another, but which are not all necessarily contagious; some of which, being not at all amenable to surgical treatment, are regarded as "medical" diseases, while others, which occur mostly in connection with surgical cases, or which lead to conditions requiring surgical relief, are usually spoken of as "surgical" diseases. As excellent and only too common examples of these zymotic diseases may be mentioned tetanus, erysipelas, puerperal fever, typhoid fever, and those varied conditions which are generally grouped under the term "blood poisoning." Those which most concern the surgeon, and those in which most remarkable relief has been obtained are erysipelas and the various forms of blood poisoning. These, in their varied manifestations, have, until recently, been literally the terror of surgeons, and in military hospitals, for instance, have been the cause of more deaths than have ever resulted from wounds directly upon the battle-field. In civil hospitals, as well as in general and private practice, the mortality from these diseases was, until twenty-five years ago, simply frightful; while frequently, and over wide areas of territory, endemics and epidemics of puerperal fever would result in the death of almost every lying-in woman. In consequence of this terrible death-rate surgeons were afraid to operate, and certain classes of operations, especially those on the abdomen and joints, were never performed, except under most exacting circumstances. But few of the present generation can actually realize the completeness of the changes brought about by the adoption of the germ-theory, and the practical effect of its use as a working basis for combating disease.
While no intelligent student at present denies that the infectious diseases—of which the above named are but a very few—are the result of the introduction into the body, from without, of minute living organisms, for the most part vegetable,—thus constituting them in reality, as they are often called, parasitic diseases,—but few are so familiar with the history of modern discovery as to appreciate the basis upon which it has been demonstrated. The proof of the germ origin of disease is the legitimate outcome of the discovery of the actual causes of fermentation and putrefaction.
Aside from the crude and often wild notions which have appeared here and there in literature of previous centuries, about the first accurate investigations bearing upon this subject were with reference to the cause of alcoholic fermentation. About the beginning of this century Appert published a monograph upon the Art of Preserving Animal and Vegetable Substances, which consisted in placing them in closely corked or stoppered bottles, and exposing these to the temperature of boiling water. Gay-Lussac, the celebrated chemist, noticed that so soon as these vessels were opened, particularly if much exposed to air, their contents began to at once ferment or putrefy. This led to investigations into the production of alcohol, and the antiseptic effect of pure oxygen-gas; from which he concluded that oxvgen is necessary at the commencement of the process, but not throughout its continuance. Some thirty years later, Schwann, by the use of the microscope, then reasonably developed, discovered in fermenting substances numerous very minute globular bodies, which had the power of reproduction, and which were present in juices or fluids undergoing alcoholic fermentation, but not in others, and which he concluded to be the exciting cause. Schwann also discovered that if, in vessels sealed by Appert's method, lie allowed air which had been previously heated to come in contact with the fluids, no change resulted; from which it was evident that it was something other than the gaseous elements of the air which provoked fermentation. Schwann's investigations were corroborated, in 1843, by Helmholtz.
Schwann's results were contested by Liebig, one of the most eminent chemists of his time, who proposed a very different theory, ascribing putrefaction to the absence of oxygen and to the upsetting of molecular arrangements. He believed that non-nitrogenous substances did not spontaneously undergo putrefaction when pure, but they must be brought into contact with some substance already undergoing change, which latter was called a ferment, and which converted the oxygen of the air into carbonic acid. According to him, the ferment was some material undergoing decomposition.
The next researches on this subject were those of Schroeder and Dusch, in 1854 who studied the question whether filtration of air would prevent the fermentation of boiled fluids to which such filtered air might have access. The material used for filtration was cotton-wool; and they showed that air filtered through it was deprived of the agencies which produce fermentation. Then came Pasteur, who repeated the experiments of his predecessors and elaborated and confirmed them. He also found that it was not necessary to filter the air of its contained particles, but that if it were simply left undisturbed until these had settled by gravity, it might then be brought in contact with putrescible substances without causing any putrefaction.
In 1870, in a lecture upon haze and dust, Tyndall demonstrated beautifully and in public the presence of countless particles in the air, as well as that these were the agencies operating to produce undesirable changes in organic substances. Both Pasteur and Tyndall, as well as others, showed, as did also Lister, that heat as well as filtration was sufficient to render these particles innocuous. As the result of these and numerous other experiments, by various observers, which there is no time here to recount, it was gradually and irrefutably established that the gases of the air, per se, are powerless to cause fermentation or putrefaction in boiled fluids or tissues, or in material germ-free when exposed. It was sufficient, in order to so purify the air, to either previously heat it or filter it through cotton-wool or through fluids inimical to germ-life, while the boiling of organic material or its subjection to the boiling heat of water was sufficient to destroy all germ-activity in it at the time, or, as we say now, to sterilize it.
In this way, and even before any minute and systematic study of bacteria,—i.e., before the inauguration of bacteriology as a separate department of scientific study,—it was practically established that the agencies which produce putrefactive changes or fermentation were minute particles which were ever present in almost every substance, and that by heat or something corresponding to filtration it was possible to remove them or destroy their activity.