Before giving a succinct account of the discovery of paludal miasma and of its natural history, I ought in the first place to state that I have not had the opportunity of reading or studying the great original treatise of Professor Salisbury. I am acquainted with it only through a resume published in the American Journal of the Medical Sciences for the year 1866, new series, vol. li. p. 51. At the beginning of my investigations I was engaged in a microscopic examination of the water and mud of swampy shores and of the marshes, also with a comparison of their microphytes with those which might exist in the urine of patients affected with intermittent fevers. Nearly three months passed without my being able to find the least agreement, the least connection. Having lost nearly all hope of being able to attain the end which I had proposed, I took some of the slime from the marshes and from the masses of kelp and Confervæ from the sea shores, where intermittent fevers are endemic, and placed them in saucers under the ordinary glass desiccators exposed on a balcony, open for twenty-four hours, the most of the time under the action of the burning rays of the sun. With the evaporated water deposited within the desiccators, I proceeded to an examination, drop by drop. I at length found that which I had sought so long, but always in vain.
The parasite of intermittent fever, which I have termed Limnophysalis hyalina, and which has been observed before me by Drs. J. Lemaire and Gratiolet (Comptes Rendus Hebdomadaires de l'Academie des Sciences, Paris, 1867, pp. 317 and 318) and B. Cauvet (Archives de Medecine Navale, November, 1876), is a fungus which is developed directly from the mycelium, each individual of which possesses one or several filaments, which are simple or dichotomous, with double outlines, extremely fine, plainly marked, hyaline, and pointed. Under favorable conditions, that is, with moisture, heat, and the presence of vegetable matter in decomposition, the filaments of mycelium increase in length. From these long filaments springs the fungus. The sporangia, or more exactly the conidia, are composed of unilocular vesicles, perfectly colorless and transparent, which generally rise from one or both sides of the filaments of the mycelium, beginning as from little buds or eyes; very often several (two to three) sporangia occur placed one upon the other, at least on one side of the mycelium.
With a linear magnitude of 480, the sporangia have a transverse diameter of one to five millimeters, or a little more in the larger specimens. The filaments of mycelium, under the same magnitude, appear exceedingly thin and finer than a hair. The shape of the conidia, though presenting some varieties, is, notwithstanding, always perfectly characteristic. Sometimes they resemble in appearance the segments of a semicircle more or less great, sometimes the wings of butterflies, double or single. It is only exceptionally that their form is so irregular.
Again, when young, they are perfectly colorless and transparent; sometimes they are of a beautiful violet or blue color (mykianthinin mykocyanin). Upon this variety of the Limnophysalis hyalina depends the vomiting of blue matters observed by Dr. John Sullivan, at Havana, in patients affected with pernicious intermittent fever (algid and comatose form). In the perfectly mature sporangia, the sporidia have a dark brown color (mykophaein). From the sporidia, the Italian physicians, Lanzi and Perrigi, in the course of their attempts at its cultivation, have seen produced the Monilia penicinata friesii, which is, consequently, the second generation of the Limnophysalis hyalina, in which alternate generation takes place, admitting that their observations may be verified. The sporangia are never spherical, but always flat. When they are perfectly developed, they are distinctly separated from their filament of mycelium by a septum--that is to say, by limiting lines plainly marked. It is not rare, however, to see the individual sporangia perfectly isolated and disembarrassed of their filament of mycelium floating in the water. It seems to me very probable that these isolated sporangia are identical with the hyaline coagula so accurately described by Frerichs, who has observed them in the blood of patients dying of intermittent fevers. But if two sporangia are observed with their bases coherent without intermediary filaments of mycelium, it seems to me probable that the reproduction has taken place through the union, which happens in the following manner: Two filaments of mycelium become juxtaposed; after which the filaments of mycelium disappear in the sporangia newly formed, which by this same metamorphosis are deprived of the faculty of reproducing themselves through the filaments of myclium of which they are deprived. The smallest portion of a filament of mycelium evidently possesses the faculty of producing the new individuals.
It is unquestionable that the Limnophysalis hyalina enter into the blood either by the bronchial mucous membrane, by the surface of the pulmonary vesicles, or by the mucous membrane of the intestinal canal, most often, no doubt, by the last, with the ingested water; this introduction is aided by the force of suction and pressure, which facilitates their absorption. It develops in the glands of Lieberkuhn, and multiplies itself; after which the individuals, as soon as they are formed, are drawn out and carried away in the blood of the circulation.
The Limnophysalis hyalina is, in short, a solid body, of an extreme levity, and endowed with a most delicate organization. It is not a miasm, in the common signification of the term; it does not carry with it any poison; it is not vegetable matter in decomposition, but it flourishes by preference amid the last.
In regard to other circumstances relative to the presence of this fungus, there are, above all, two remarkable facts, namely, its property of adhering to surfaces as perfectly polished as that of a mirror, and its power of resistance against the reagents, if we except the caustic alkalies and the concentrated mineral acids. This power of resisting the ordinary reagents explains in a plausible manner why the fungus is not destroyed by the digestive process in the stomach, where, however, the acid reaction of the gastric juice probably arrests its development--is that of the schistomycetes in general--and keeps it in a state of temporary inactivity. This property of adhering to smooth surfaces explains perhaps the power of the Eucalyptus globulus in arresting the progress of paludal miasm (?). But it is evident that other trees, shrubs, and plants of resinous or balsamic foliage, as, for example, the Populus balsamifera, Cannabis sativa, Pinus silvestris, Pinus abies, Juniperus communis, have equally, with us, the same faculty; they are favorable also for the drying of the soil, and the more completely, as their roots are spreading, more extended, and more ramified.
In order to demonstrate the presence of the limnophysalis in the blood of patients affected with intermittent fever during the febrile stage, properly speaking, it appeared necessary for me to dilute the blood of patients with a solution of nitrate of potassa, having at 37.5°C. the same specific gravity as the serum of the blood. With capillary tubes of glass, a little dilated toward the middle, of the same shape and size as those which are used in collecting vaccine lymph, I took up a little of the solution of nitrate of potassa above indicated. After this I introduced the point of an ordinary inoculating needle under the skin, especially in the splenic region, where I ruptured some of the smallest blood-vessels of the subcutaneous cellular tissue. I collected some of the blood which flowed out or was forced out by pressure, in the capillary tubes just described, containing a solution of potassa; after which I melted the ends with the flame of a candle. With all the intermittent fever patients whose blood I have collected and diluted during the febrile stage, properly speaking, I have constantly succeeded in finding the Limnophysalis hyalina in the blood by microscopic examination.
It is only necessary for me to mention here that it is of the highest importance to be able to demonstrate the presence of fungus in the blood of the circulation and in the urine of patients in whom the diagnosis is doubtful. The presence of the Limnophysalis hyalina in the urine indicates that the patient is liable to a relapse, and that his intermittent fever is not cured, which is important in a prognostic and therapeutic point of view.
When the question is to prevent the propagation of intermittent fevers, it is evident that it should be remembered that the Limnophysalis hyalina enters into the blood by the mucous membrane of the organs of respiration, of digestion, and the surface of the pulmonary vesicles. We have also to consider the soil, and the water that is used for drinking.