Speculum

“ A closed end speculum, with a proportionate slot and smooth corners, can be slowly rotated without any difficulty where the mucous membrane is not very loose and baggy and no prominences in the route. ”

“ The patient having been fixed in the lithotomy position in the manner described by Soranus:
‘The operator is to make the examination with a speculum (διόπτρα) proportioned to the age of the patient. The person using the speculum should measure with a probe the depth of the woman’s vagina, lest the priapiscus of the speculum (τοῦ τῆς διόπτρας λωτοῦ) being too long it should happen that the uterus be pressed on. If it be ascertained that the tube is longer than the woman’s vagina, folded compresses are to be laid on the labia in order that the speculum may be laid on them. ”

“ This immense literary undertaking was completed under the patronage of King Louis IX. by Vincent, a Dominican friar, who died at the beginning of the last quarter of the thirteenth century. His Majus Speculum is not the first book of general information, but it is the first deserving the name of Encyclopedia in the full sense of the word that we have. It is divided into three parts--the Speculum Naturale, Doctrinale, and Historiale. The only one which interests us here is the Speculum Naturale, which fills a huge folio volume of nearly a thousand pages, closely printed in double columns. ”

“ The laryngeal spring, or speculum, was more successful than the wire, but it had one of the faults of the wire spring. Into the slit between the two portions of the speculum the inflamed mucous membrane was apt to force itself, so that before long difficulty of breathing would recur. Besides, if the spring which kept the blades of the speculum apart were weak, the instrument would fail of its purpose in {331} keeping the mucous membrane apart, while, if it were strong, the pressure of the blades would cause ulceration. ”

“ The speculum must pass sufficiently far below the tip of the epiglottis so that the latter will not slip. 6. Too deep insertion must be avoided, as in this case the speculum goes posterior to the cricoid, and the cricoid is lifted, exposing the mouth of the esophagus, which is bewildering until sufficient education of the eye enables the operator to recognize the landmarks. 7. The patient's head is lifted off the table by the spatular tip of the laryngoscope. Actual lifting of the head will not be necessary if the patient is fully relaxed ”

“ Driven, then, from the field of real disease, these advocates of the Speculum are obliged to invest with a false character ailments that the profession has hitherto regarded as too trifling to [Pg 62] admit of any save the simplest treatment.... The Speculum has been greatly extolled as the means of conveying appliances immediately to the parts affected. ”

“ As the fifteenth book of the Speculum Doctrinale is a summary of the Speculum Naturale, so the Speculum Historiale may be regarded as the expansion of the last book of the same work. It consists of thirty-one books divided into 3793 chapters. The first book opens with the mysteries of God and the angels, and then passes on to the works of the six days and the creation of man. It includes dissertations on the various vices and virtues, the different arts and sciences, and carries down the history of the world to the sojourn in Egypt. ”

“ And as the latest edition of the Psalter, printed in the old types, appeared in 1516, it would be necessary to suppose that movable wood type was in vogue up to that date. No one has yet demonstrated, or attempted seriously to demonstrate, the possibility of printing a book like the Speculum in movable wooden type. All the experiments hitherto made, even by the most ardent supporters of the theory, have been woful failures. ”

“ If we take a speculum by means of which a view may be had of the interior of the eye, and fixate a definite point on the retina of the horse, and then make a slight movement of the head horizontally, we find that the point fixated moves—apparently at least—toward the border of the pupil. ”

“ Apart from the final date (1471) for them there is also evidence that the Speculum type 1 existed a considerable time before 1474, as in that year the bookbinder Cornelis used fragments of a Donatus printed in that type in the binding of an account book of the cathedral church at Haarlem. Their types and workmanship, moreover, compel us to place them before the Valla, Pontanus and Saliceto (or Pius) types. ”

“ For a long time past we had had speculums for the eye, for the ear, for the throat, etc.; why should we not succeed in inventing a speculum for the brain? There were already self-registering thermometers, barometers, magnetometers, photometers, etc.; why should we not have the self-registering enkephalometer? machines which [88] in a few minutes, and by means of a few figures, would indicate the exact degree and amount of knowledge acquired by the individual to whose cerebrum the instrument might be applied! What a splendid invention, both for examiners and candidates, this would have been! ”

“ This leaves the right hand free for manipulation. The largest possible speculum should be used, in order to give the maximum amount of room and illumination. It should only be introduced into the meatus as far as the adaptable cartilaginous portion permits—about half an inch in the adult—and not forced into the bony portion. The utmost gentleness is essential in order to obtain the confidence of the patient; this is absolutely necessary for the performance of the various small operations upon the auditory canal and tympanic cavity under local anæsthesia. ”

“ As a Speculum takes in and reflects more of its Object, when plac'd at a great distance from it, than when nearer; because it reflects according to the apparent Magnitude of the Body at such a distance, which is less: So also the Ecchoing Body, being remov'd farther off, reflects more of the Sound, than when nearer. And this is the reason, why some Ecchoes repeat but one Syllable, some one Word, and some many. ”

“ At last, in 1839, a 3-ft. speculum was successfully cast and mounted as a Newtonian. The details of its construction were communicated to the Royal Society on 9 May 1840 (Phil. Trans. cxxx. 503) , and the results of observations made with it upon some of the nebulæ, on 19 June 1844 (ib. cxxxiv. 321) . The methods of work being now well under control, two specula, each six feet in diameter, four tons in weight, and of fifty-four feet focus, were cast, after various failures, in 1842 and 1843. ”

“ A convex speculum is ground and polished in a concave dish or tool which is a portion of a sphere, and a concave speculum is ground upon a convex tool. The inner surface of a sphere brings parallel rays to a focus at one fourth of its diameter, as represented in the following figure, where C is the centre of the sphere on which the concave speculum AB is formed, and F the focus where parallel rays from a distant object would be united, after reflection, that is, at one half the radius, or one fourth of the diameter from the surface of the speculum. ”

“ One or two folio editions of the Speculum in Latin, printed (pictures and text) from wooden blocks, and consisting most likely of 32 if not more chapters, but of which only ten sheets (twenty leaves) , and six separate woodcuts (cut up into twelve halves, for the Veldener 4to edition of 1483) have come down to us. Of one of these xylographic editions, at least of ten sheets of it, three issues are known to have been made in combination with type-printed leaves (see below) . ”

“ Great care should be exercised, when introducing the speculum, not to scratch the mucous membrane of the septum, for this will give rise to pain and start hemorrhage, both of which are to be avoided as much as possible. When applications are to be made to the mucous membrane of the septum or turbinated bones, or when operations are to be performed within the cavity, it is best to employ an instrument called a nasal dilator, of which there are a large number of different forms, the most satisfactory of which is shown in Fig. ”

“ In our British Phasgonura viridissima it appeared to me that the serrated nervure is rubbed against the rounded hind corner of the opposite wing, the edge of which is thickened, coloured brown, and very sharp. In the right wing, but not in the left, there is a little plate, as transparent as talc, surrounded by nervures, and called the speculum. In Ephippiger vitium, a member of this same family, we have a curious 355subordinate modification ”

“ The cells which line the cavity at the back of the nose, the tubes of the lungs, and other parts of the body, have a few cilia on their free surface, and it is in them that the structure of these organs can best be made out. At the foot of each cilium is a minute globule, from which a fine fibril passes into the cell, and the fibrils, collectively forming a leash, are attached to its opposite end. (See Diagram 17.) It seems highly probable that the globule is a centrosome giving rise to two fibrils, one attached as described, the other passing up one side of the cilium, and fast to its apex. ”

“ On examining this piece, it will be observed that it is not formed in regular layers like the rest of the shell; while the true operculum is of a regularly laminated structure, having a nucleus and receiving obliquely deposited additions, either in a lateral spiral or concentric direction. It is attached to the posterior part of the foot on the upper surface; and when the animal retires within its shell, that part of the foot enters last, drawing the operculum after it, and thus closing the aperture. ”

“ In the one animal (Palæostraca) the foremost pair of mesosomatic appendages forms the operculum, which always bears the terminal generative organs and is fused in the middle line. In many forms, essentially in Eurypterus and the ancient sea-scorpions, the operculum was composed of two segments fused together: an anterior one which carried the uterus, and a posterior one which carried the first pair of branchiæ. ”

“ The operculum expands medially to merge with the main part of the otic capsule (Fig. 20g) . The lateral edge of the operculum expands ventrally and then dorsomedially to form a complete tube. Slightly more posteriorly the cartilaginous lateral edge of the otic capsule, lateral to the operculum, dissipates into connective tissue and finally disappears, leaving the posterior end of the operculum as the most distal element of the otic capsule (Fig. 20h) .
[Pg 31]
Fig. ”

“ The leaves, which are only employed in a fresh state, are 6 to 10 inches in length, with long stalks, ovate, often unequal at the base, acuminate, coarsely dentate with a few spreading teeth. They evolve an offensive odour when handled.
Microscopic Structure—The testa is built up of the same tissues as in D. Stramonium, but the thick-walled cells constituting the spongy part are far larger, and distinctly show numerous secondary deposits, making a fine object for the microscope. ”

“ The body is a sac, branched in the adult, but simple in the young; its continuous cavity is everywhere lined with choanocytes, its wall is traversed by inhalant pores, and its cavity opens to the exterior at the distal end by an osculum. The simple sac-like young is the well-known Olynthus of Haeckel—the starting-point from which all sponges seem to have set out. Two processes are involved in the passage from the young to the adult, namely, multiplication of oscula and branching of the original Olynthus tube or sac. ”

“ The cells are often pigmented, and they are covered by a much thicker cuticula than that of the stomach, but which is not so thick and hard as that of the œsophagus and proventriculus. The very refringent cuticula is not thrown up into ridges, though in some parts it is covered with delicate conical spines, which are very short. “The epithelium and underlying connective tissue (tunica propria) are thrown up into six folds, which run longitudinally, being regular in the ileum and rectum (as the rectal glands) , but very irregular in the colon. ”

“ The Exoplasm of the Peripylea.—The extracapsular protoplasm of the Spumellaria or Peripylea is in communication with the intracapsular sarcode by the innumerable fine pores of the capsule-membrane, and like these pores is evenly distributed over the whole surface. The sarcomatrix which immediately surrounds the central capsule is moderately strong, and sends out innumerable long, thin pseudopodia, which probably correspond to the pores of the membrane. Their number is markedly greater in the Spumellaria than in the other three legions. ”

“ Taking all in all, the only element of the neuromuscular mechanism that is really present in sponges is the effector as represented by the sphincters of the pores and oscula.
If independent effectors occur in sponges, it is not unlikely that they may be present in the higher animals, and as possible examples of these the sphincter pupillæ of the eye in vertebrates and the heart-muscle may be considered. The sphincter pupillæ is a ring of muscle imbedded in the iris and surrounding the pupil in the eyes of most vertebrates. ”

“ In the Sponge, which is perhaps the nearest type of all, we have the movable pulsating cilium and true animal cellular tissue, and along with this the spicular or fibrous skeleton, these structures leading to an entire change in the mode of life and subsistence. In the higher types of animals it is the same. Even in the highest we have white blood-corpuscles and germinal matter, which, in so far as we know, carry on no higher functions of life than those of an Amœba ”