Dr. Bacon is of opinion that the cowpox is now what it was at the beginning. There are instances, in which it has passed from one human subject to another for more than thirty years, consequently through fifteen or sixteen hundred individuals, but yet in which no degeneration has taken place. He nevertheless admits that recent lymph from the cow should be preferred, when it can be procured; he is further of opinion that the occurrence of smallpox after inoculation does not exceed in number the cases of smallpox after smallpox. My own experience confirms these views. I was in practice in Bordeaux during the prevalence of what is called smallpox in vaccinated cases,—the cases were rare, doubtful, and very seldom fatal.
There is little doubt that the smallpox would sweep away thousands of our dense population but for the protecting power of vaccination, the failure of which, ought more frequently to be attributed to the vaccinator, or the constitution of the patient, than to Jenner’s immortal discovery. Dr. Severn has just published an essay on this most important subject, and it appears by his statistical tables, that such has been the decrease of mortality since the introduction of vaccination, that the number of patients admitted into the smallpox hospital from 1775 to 1800,—were 7017—the deaths 2277—whereas from the year 1800 to the year 1825, the number admitted was 3943, and the deaths 1118—not half the number, although the population of London had doubled during that period. Dr. Severn further calculates that the proportion of failures is 6 in 3000.
We read with feelings of deep regret in his late bibliography, that the man at whose intercession the magic of his name obtained the liberation of Napoleon’s prisoners, could not obtain an appointment for the members of his own family from the British Government; nay, the College of Physicians despite the exertions of Dr. Baillie, refused to admit him to a fellowship in their learned body. It was when reflecting on such national ingratitude, that he wrote to a friend, “Never aim, my friend at being a public character, if you love domestic peace.” And not long before he terminated his invaluable career he made this remarkable expression: “I am not surprised that men are not thankful to me; but I wonder that they are not grateful to God for the good which he has made me the instrument of conveying to my fellow-creatures.”
It is in vain that France with her usual jactance pretends that the first idea of vaccination arose in that country, they have no more claim to the discovery than their Marshals to Wellington’s immortal glory.
GENERATIVE ANIMALCULES.
Microscopic experiments daily demonstrate the existence of myriads of animalcules in every substance. They have recently been discovered in the progress of certain crystallizations; and some philosophers maintain that most inorganic bodies are formed of the remains of organic substances. The existence of animalcules in the generative secretion was first noticed by Lewis Hamme, a young German student, and shown by him to Leeuwenhoeck, who published an account of them. Hartzoeken wrote upon the subject the following year, and asserted that he had seen these animalcules three years before they had been observed by Hamme. This curious subject soon attracted the notice, not only of physiologists, but of priests, artists, and even courtiers, for we find our Charles II. making curious inquiries on this investigation. Although many opticians could not discover these creatures, the eyes of courtiers were more keen than theirs, and to gratify their royal master’s depravity, described them most minutely. Their length was 3⁄100000 of an inch, their bulk such as to admit the existence of 216,000 in a sphere whose diameter was the breadth of a hair, and their rate of travelling nine inches in the hour. They saw them in the seminal secretion of every animal; and, what was still more remarkable, they were of a similar size whatever might have been that of the animal: they saw them in the sprat and in the whale; they could distinguish the male from the female; and they all moved along in gregarious harmony like a flock of sheep: nay, more; Dalenpatius actually saw one of them, more impatient than his companions, burst from his ignoble shackles, and actually assume the human form. At other times they were discovered swimming in shoals to given points, turning back, separating, meeting again, and frisking about like golden fish in a pond. Kauw, Boerhaave, Maupertius, Lieuland, Ledermuller, Monro, Nicholas, Haller, and indeed most of the philosophers of Europe, were convinced of their existence.
Buffon, however, and other naturalists, contended that these were not animalcules, but organic particles; and Linnæus imagined them to be inert molecules, thrown into agitation by the warmth of the fluid. Finally, to determine the question, Spallanzani began an assiduous course of observations and experiments. He found these animalcules in the human species to be of an oval form, with a tail tapering to a point. This appendage, by moving from side to side, propelled them forward. They were in constant motion in every direction. In about twenty-three minutes their movements became more languid, and in two or three hours they generally died. The duration of their life, however seemed to depend, in a great measure, on the temperature of the medium: at 2° (Reaumur) they died in three quarters of an hour; while at 7° they lived two hours, and at 12½° three hours and three quarters. If the cold was not too intense, they recovered upon the temperature being raised; when only 3° or 4°, they recovered after a lethargy of fourteen hours; and according to the less intensity of the cold, they might be made to pass from the torpid to the active state more frequently. They were destroyed by river, ice, snow, and rain water; by sulphur, tobacco, camphor, and electricity; even the air was injurious to them: in close vessels their life was prolonged to some days, and their movements were not constant and hurried. They were of various sizes, and perfectly distinct from all species of animalcules found in vegetable infusions, &c. In short, Spallanzani completely confirmed the principal observations of Leeuwenhoeck, and satisfactorily explained the sources of the inaccuracies of other inquirers. Prevost and Dumas have recently confirmed the observations of the Italian physiologist.
This doctrine of life being perpetuated by the transmission of animated particles, or animalcules, is by no means of modern date. We find this theory advanced by Hippocrates, and Aristotle, and Plato. Democritus described worms that assumed, in the progress of their development, the human form; and Lactantius thus refuted his ideas: “Erravit ergo Democritus, qui vermiculorum modo putavit homines effusos esse de terrâ, nullo auctore, nullâque ratione.” Hippocrates plainly says, that the seminal secretion was full of animalcules, whose several parts were developed, and grew afresh; that nothing did exist that had not pre-existed; and that what we term birth was nothing more than that transition of these hitherto imperceptible animalcules from darkness to light.
Gesner has endeavoured to prove that the word ψυχή, so frequently found in the writings of Hippocrates, and translated anima, was synonymous with insectum, animalculum, papilio. Plato, when expressing himself on this curious subject, compares the matrix to a fertile field, in which animalcules are gradually developed, at first of such a small size that they are imperceptible, but, by taking the food prepared for them, grow in strength until they are brought to light in a state of perfect generation; and St. Augustine thus follows: “Hunc perfectionis modum sic habent omnes ut cum illo concipiantur atque nascuntur; sed habent in ratione, non in mole, sicut ipsa jam membra omnia sunt latenter in semine; cùm etiam natis nonnulla desint, sicut dentes, ac si quid ejusmodi.” In the works of Seneca we also find the same notions: “In semine omnis futuri hominis ratio comprehensa est, et legem barbæ et canorum nondum natus infans habet; totius enim corporis, et sequentis ætatis, in parvo occultoque lineamenta sunt.”