2716. William Hawkes, Birmingham-A new or improved machinery 2752. Richard Eaton, 2, Sussex-terrace, New-road, Battersea-Imfor applying steam power to the ploughing of land, and other agricultural operations. 2717. Esteves Blanchon, Blois, France-Machinery and apparatus for Dated 18th November, 1856. 2719. John Wilson, West Bromwich, Stafford - Improvements in provements in apparatus for buffing on railways, and for other purposes. Dated 21st November, 1856. 2753. Louis Dartois, 39, Rue de l'Echiquier, Paris-An improved 2757. John William Clare, White-street, Saint George the Martyr, 2759. 2722. Frederick Arthur Magnay, Taverham Mills, Norwich-Im- 2724. Samuel Dyer, Bristol-Improved mechanism, applicable to 2725. John Grieve, Bank-park, Tranent, Haddington-Improvements in chimney cans. 2726. Henry Bessemer, Queen-street-place, New Cannon-street-Improvements in the manufacture of iron. [From Gazette, December 5th, 1856.] Dated 13th September, 1856. Dated 15th November, 1856. Dated 19th November, 1856. 2765. William Edward Newton, 66, Chancery-lane-Improvements Richard Archibald Brooman, 166, Fleet-street-A method of Dated 22nd November, 1856. 2769. William Thomas Henley, St. John's-street-road, Clerkenwell -Improvements in electric telegraphs. and apparatus connected therewith. 2771. 2773. Alexander Robert Terry, 24, Great George-street, Westminster -Improvements in sawing, splitting, cutting, and binding kindling wood. Edward Tucker, Belfast-Improvements in preparing and dryRichard Archibald Brooman, 166, Fleet-street-Improvements ing glue and gelatinous matter. in the manufacture of artificial wines, or beverages to be substituted for wines, and in apparatus for aiding fermentation. (A communication.) William Edward Laycock, Sheffield-Improvements in looms for weaving. Dated 24th November, 1856. 2681. The Honourable William Erskine Cochrane, 5, Osnaburgh- 2777. terrace, Regent's park-Improvements in the permanent way of railways. 2727. William Brindley, Moorgate-street-Improvements in the treatment and application of papier maché for covering floors, roofs, and other like useful purposes. 2729. Henry John Distin, 31, Cranbourn-street, Leicester-squareImprovements in cornets and other wind musical instruments. (A communication.) 2730. William Smith Churchill and James Bradshaw, Stalybridge, Cheshire-Improvements in machinery or apparatus for drying yarns or fabrics, applicable to machines for sizing or dressing yarns or threads to prepare them to be woven. 2731. John Jones, Middlesborough-on-Tees, Yorkshire, and Edward 2793. Henry Bougleux, Leghorn-Improvements in the construction Jones, Liverpool-Improvements in the manufacture or production and treatment of metal castings. 2732. John Lord, Rochdale-An improved admixture or compound 2733. James, Earl of Caithness, Barrogili-castle, Caithness, N.B.- 2739. Samuel Fox, Deepcar, Sheffield-Improvements in machinery 2740. Louis Adolphe de Milly, Paris-Improvements in the manufacture of fatty acids. 2741. Samuel Fox, Deepcar, Sheffield-Improvements in heating steel wire and tubes, also ribs and stretchers of umbrellas and parasols for hardening, and in apparatus for straightening wire and tubes. Dated 20th November, 1856. 2742. Edwin Salt, Bolton-le-Moors-An improved paper-cutting machine. 2743. James Montgomery Gilbert, Manchester-Improvements in certain machines for etching or engraving. 2787. 2789. John Orr, Glasgow-Improvements in the manufacture of pile fabrics. 2745. Peter Armand le Comte de Fontainemoreau, 39, Rue de man. 1606. Julien François Belleville. 2746. Charles François Jules Fonrobert, Berlin-Improvements in the mauufacture of boots and shoes. (Partly a communica- PATENTS ON WHICH THE THIRD YEAR'S STAMP DUTY HAS BEEN PAID. tion.) 2747. Charles François Jules Fonrobert, Berlin-Improvements in the manufacture of insulated wires for electric telegraphs. (Partly a communication.) 2748. Thomas Francis Joyce, Birmingham-Improvements in join- 2750. Robert Brock Benson, New York-Improvements in reefing December 1st. 2891. Wm. Frederick Plummer. 2812. Jonathan Saunders. Journal of the Society of Arts. FRIDAY, DECEMBER 19, 1856. the surrounding ocean and arranging in their own frail tissues the lime which is ever being carried into the ocean by the rivers that drain the land,-by the chemical power which they at the same time possess of adding to that soluble caustic lime the carbon which results from the low combustion of their vital action-relieve the sea of that mineral element which in excess would prove noxious to animal life, and at the same time lay the foundation of those enormous masses of carbonate of lime which constitute the coral islands and coral reefs that are met with in most of the tropical and warmer parts of the ocean. These examples of calcified animal tissues, after The Fifth Ordinary Meeting of the One having been subjected to the mechanical action of the Hundred and Third Session was held on Wed-surf-waves, to the chemical influences of volcanic heat, FIFTH ORDINARY MEETING. WEDNESDAY, DEC. 17, 1856. nesday, the 17th inst., J. Griffith Frith, Esq., in the chair. expansive and upheaving forces of the same plutonic and to those changes of position which are due to the agency, become those fertile tracts of dry land which form the chalk cliffs and the limestone rocks of actual con tinents. The uses which man derives from analogous calcified parts of animal tissues are comparatively few and insignificant. There is a certain commerce in shells which are used for the purpose of cameo works and other ornaments, and a smaller amount of traffic in certain forms of corals. The bones of the vertebrated animals, which are hardened, not like shells, by carbonate, but principally by phosphate of lime, are used largely in certain chemical operations. A few bones, from their greater degree of density, are serviceable for mechanical purposes; but the calcified tissue of highest value in the arts, and which, from the earliest periods of human history, has been the object of chief research for ornamental purposes, is ivory. This term is properly applied only to the substance which forms the main body of the long, projecting, hornlike teeth, called tusks in the elephant. Ivory is the principal subject which, agreeably with the request that I have been favoured with by the Council of the Society, I have selected for the few observations which I shall have the honour to make this evening. I wish it were in my power to deduce from the results of the numerous and minute researches of anatomists and physiologists into the structure and mode of growth of this valuable substance, ivory, any conclusions which might lead to procedures calculated to improve its qualities, or which might be suggestive of aught that might tend to increase the quantity and diminish the price of ivory. But I am compelled to admit that the researches of science do not, in this particular; lend any efficient aid to the arts in reference to ivory. All the parts of animal bodies are, at their beginning, in a state of fluid. In this plasma, or formative fluid, there are numerous points or centres which, from subsequent phenomena, may be called centres of attractive or assimilative force, antagonised by centres of repellant or excretive force. The first organic forms observed, as the consequence of the co-ordinated operations of these modes of force are minute vesicles with usually central parts or nuclei, and called cells or nucleated cells. By the properties and actions of these cells, the different elements in the plastic fluid are selected, localised, and specially arranged for the formation of the future organs. Some aggregate the albuminous principle, to form the nervous system-others, the fibrinous principle, to form the muscles-others, the The substance of the teeth of other animals besides gelatinous principle, which becomes the basis of a vast the elephant is an article of commerce. Formerly, the variety of organs. The blood may be regarded as the name ivory was given to the main substance of the continued and somewhat modified formative plasma, teeth of all animals; but it is now by the best meandering or circulating in specially organised tubes, or anatomists and physiologists, restricted to that modithrough the interspaces, and in the substance, of the several fication of dentine or tooth-substance which, in transtissues and organs. Certain parts, which have the gela- verse sections or fractures, shows lines of different tinous principle for their basis, possess the property of colours or striæ proceeding in the arc of a circle, and combining with that basis the mineral or earthy elements forming by their decussations minute curvilinear lozengecontained in the plasma, or blood. Some of these tissues shaped spaces. By this character, which is presented by consolidate themselves by the addition of pure flint; every the smallest portion of an elephant's tusk in transothers and the majority-by the addition of salts of verse section or fracture, true ivory may be distinguished lime, either lime in combination with carbonic acid, from every other kind of tooth-substance, and from every or lime in combination with phosphoric acid, or with counterfeit, whether derived from tooth or bone. It is varied proportions of both salts, and with the addi-a character-this engine-turned decussating appearancetion, in a few cases, of fluate of lime. It is these con- which is as characteristic of fossil as of recent ivory. solidated, hard, resisting textures of animal bodies that Although, however, no other teeth except those of the have been found of most use in the arts. They are elephant present the characteristic of true ivory, there are known by the names of bones, and shells, coral, and teeth in many other species of animals which, from their ivory. Art, however, derives a small amount of profit large size and the density of their principal substance, from the calcified or silicified tissues of dead animals are useful in the arts for purposes analogous to those for compared with that which Nature avails herself of. which true ivory is used; and some of these dental tissues, They subserve and are essential to her in some of her such as those of the large tusks of the hippopotamus, mightiest operations on the surface of this earth. The are more serviceable for certain purposes, especially in countless and widely diversified species of soft gelatinous the manufacture of artificial teeth, by the dentist, than polypes, by the power which they possess of selecting from any other kind of tooth-substance. The utility of teeth in commerce and the arts depends however, to the commercial relations of ivory, it is chiefly chiefly on a peculiar modification in their laws of growth. worthy of notice that in the Asiatic elephants, tusks of For the most part teeth-as in our own frames-having a size which gives them the value of ivory in commerce attained a certain size and shape, cease to grow. They are peculiar to the males, whilst in the African eleare incapable of renewing the waste to which they are phants, both males and females afford good-sized tusks, liable through daily use, and when worn away or affected | although there is a sexual difference of size in this speby decay, they perish. Certain teeth in man and the cies, those of the males being the largest. In former majority of the mammalia, are succeeded by a new tooth times, and, as it would seem, before man existed to avail after the old one is worn away and shed, but this, with himself of this beautiful animal substance for use or orvery few exceptions, occurs but once in the course of nament, the large quadrupeds furnishing true ivorylife. Teeth of this kind are said to be of limited growth, proboscidian quadrupeds, as they are termed, from their but there are other teeth, such as the front teeth of the peculiar prehensile nasal appendage-were much more rat, rabbit, and all the rodent tribe, the tusks of the boar widely spread over the globe, and existed in far greater and hippopotamus, the long descending canine tusks of numbers than at the present day-more numerous in inthe walrus, the still longer spiral horn-like tusk of the dividuals-more numerous in species-manifesting so narwhal, and the ivory tusks of the elephant, which are great diversities in the conformation of their grinding endowed with the property of perpetual growth, that is, teeth, as to have led the naturalist and the palæontothey grow as long as the animal lives. In the case of logist to divide them into two genera, called elephas teeth of limited growth, the formative organ may be said and mastodon. A true elephant roamed in countless to have a short life. In the case of teeth of unlimited herds over the temperate and northern parts of Europe, growth, the life of the formative organ is coequal with Asia, and America. This was the creature called by the that of the individual. The formative organ or matrix Russians, mammoth; it was warmly clad with both hair of a tooth, consists of a soft conical pulp, similar in shape and fur, as became an animal deriving its sustenance from to the first formed summit of the tooth. It is enclosed the leaves and branches of trees which grow as high as in a membranous bag, which is reflected from its base. the 65th degree of north latitude. This bag is called the capsule. In some teeth there is a third Some of the ivory of commerce is, or used to be, derived soft organ which is between the bag and the pulp, and con- from the tusks of this extinct species, of which the innects them for a greater or less extent together. Each of dividual found frozen, with all its soft parts and integuthese three soft parts of the matrix-the pulp, the cap-ments, in the icy soil of Siberia, may be known to all. sule, and the intervening substance-has its own peculiar structure and mode of action upon the blood that circulates through it, by virtue of which it selects certain hardening or earthy principles-chiefly phosphate of lime-and deposits the particles thereof after a fashion peculiar to itself whence result different dental tissues. That which is formed by calcification of the pulp is called dentine: that which is formed by calcification of the capsule is called cement: the intermediate substance, when present, forms the enamel. In teeth of unlimited growth fresh pulp, fresh capsule, and in some instances also fresh enamel-organ are formed and added to the pre-existing constituents of the tooth matrix, in proportion as these are calcified or converted into tooth substance; and as fast as the ivory and enamel may be worn away from the summit of such a tooth, will ivory and enamel be formed at its base, and thus the growth of the tooth is uninterrupted. The ratio of the addition of the formative principles is at first greater than the ratio of abrasion, and the tooth not only grows, but increases in size. When, however, the animal has attained its own full growth, the tooth for the most part is reproduced without increase of size, or at most augments only in length, and that in cases where its summit is not perpetually worn down by being opposed to that of an opposite tooth. The tusks of the hippopotamus, like the incisors of the rodents, are maintained of a certain definite shape, by being opposed to one another, but the tusks of the walrus and of the elephant, as it would seem, through the absence of opposing teeth, acquire proportionately greater length, exhibiting, indeed, the largest size to which teeth attain in the animal kingdom, and with these preliminary remarks upon the calcified tissues of animals in general, and on the general laws of dentition in the mammalian class, I proceed to the specific subject of the present discourse, which is the structure and formation of the teeth of the elephant, from which true ivory is derived. Now, I may observe, that in the present creation elephants are restricted to the African and Asiatic continents. The African elephant, as is well known, is a distinct species from the Asiatic one, and some of the Asiatic elephants of the larger islands of the Indian Archipelago as those of Sumatra-if not specifically distinct from the elephants of Continental Asia, form, at all events, a strongly marked variety. With reference, Then, there was an elephant of Southern Europe and Asia Minor,-a mastodon peculiar to the temperate and warmer parts of North America,-another species of mastodon in Central America, and two or more mastodons in South America. Australia appears likewise to have had its great proboscidian ivory-producing quadruped. The number of extinct elephants and mastodons which formerly existed in tropical Asia, and which have been restored by Cautley and Falconer, has surpassed all anticipation. No imagination can calculate the quantity of the valuable material of ivory that has been formed and has perished on this earth prior to the period of human history. At the present day, commerce is reduced to seek for that precious commodity in the tropics of the two continents-Africa and Asia. It is, of course, from our intimacy with the two existing species that our knowledge of the nature of ivory has been chiefly derived. The dentition of the genus Elephas, the sole existing modification of the once numerous and various Proboscidian family, includes two long tusks (See i in the annexed figure), one in each of the premaxillary bones, and large and complex molars (ib. m 3, m 5, m 2) in both jaws: of the latter there is never more than one wholly, or two partially,' in place and use on each side at any given time, the series continually being in progress of formation and destruction, of shedding and replacement; and, in the elephants, all the grinders succeed one another, horizontally, from behind forwards. The total number of teeth developed in the elephant appears to be d 1-1 3-3 3-3 d m 3-3 من m =28. 3-3 The two large permanent tusks are preceded by two small deciduous ones, and the number of molar teeth which follow one another on each side of both jaws is certainly not less than six, of which the last three answer to the last three in the mastodon, and to the true molars of other diphyodont placental mammals. I have shown in my "Odontography" that "The deciduous tusk makes its appearance beyond the gum between the fifth and seventh months: it rarely exceeds two inches in length, and is about a third of an inch in diameter, where it protrudes from the socket: the fang is solidified, and contracts to its termination, which is commonly a little bent, and is considerably absorbed by the time the tooth is shed, which takes place between the first and second years. The socket of These incisive teeth of the elephant not only surpass other teeth in size, as belonging to a quadruped so enormous, but they are the largest of all teeth in proportion to the size of the body; representing in a natural state those monstrous incisors of the rodents which are the result of accidental suppression of the wearing force of the opposite teeth. The tusks of the elephant, like those of the mastodon, consist chiefly of that modification of dentine which is called "ivory," and which shows, on transverse fractures or sections, striæ proceeding in the arc of a circle from the centre to the circumference in opposite directions, and forming by their decussations curvilinear lozenges. This character is peculiar to the tusks of the proboscidian pachyderms, and is characteristic of true ivory. In the Indian elephant there is a well-marked sexual difference in the growth of the tusks; they are always short and straight in the female, and less deeply implanted than in the male, she thus retaining, as usual, more of the characters of the immature state. In the male they have been known to acquire a length of nine feet, with a basal diameter of eight inches, and to weigh 150 lbs.; but these dimensions are rare in the Asiatic species. Mr. Corse, speaking of the variety of Indian elephant called "Dauntelah," from its large tusks, which project almost horizontally, with a slight curve upwards and outwards, says, "The largest I have known in Bengal did not exceed seventy-two pounds avoirdupois; at Tiperah they seldom exceed fifty pounds." There are the permanent tusk in a new-born elephant is a round cell, about three inches in diameter, situated on the inner and posterior side of the aperture of the temporary socket." The permanent tusks cut the gum when about an inch in length, a month or two usually after the milk-tusks are shed. At this period, according to Mr. Corse, the permanent tusks are "black and ragged at the ends; when they become longer, and project beyond the lip, they soon are worn smooth by the motion and friction of the trunk." varieties of the Dauntelah in which the large tusks of the male are nearly or quite straight, and in a more marked breed, called " Mooknah," the tusks are much smaller, are straight, and point directly downwards, These ascertained varieties in an existing species ought to weigh with the observers of analogous varieties in the teeth of fossil proboscidians before they pronounce definitely on their value as characters of distinct species. More anomalous varieties occasionally present themselves in the Indian elephant, as, when one tusk is horizontal and Their widely open base is fixed upon a conical pulp, the other vertical, or when, from some distortion of the which, with the capsule surrounding the base of the tusk alveolus, a spiral direction is imposed upon the growth of and the socket, continues to increase in size and depth, the tusk, as in that specimen figured by Grew in the obliterating all vestiges of that of the deciduous tusk," Rarities of Gresham College," and which is now in the and finally extending its base close to the nasal aper- Museum of the Royal College of Surgeons, London. ture. The ivory of the tusk is formed by successive The tusk of the elephant is slightly moveable in its calcification of layers of the pulp, in contact with the socket, and readily receives a new direction of growth inner surface of the pulp cavity; and, being subject to no from habitual pressure. This often causes distorted habitual attrition from an opposed tooth, but being worn tusks in captive elephants, and Cuvier relates the mode in only by the occasional uses to which it is applied, it ar- which advantage was taken of the same impressibility rives at an extraordinary length, following the curvo in order to rectify the growth of such tusks in an originally impressed upon it by the form of the socket, elephant kept at the Garden of Plants in Paris. and gradually widening from the projecting apex to that part which was formed when the matrix and the socket had reached their full size. See Mr. Corse's Memoir on the Teeth of the Elephant, in "Philosophical Transactions." 1799, p. 211. A good figure of -the deciduous tusk is given in Plate 5. The tusks of the extinct Elephas primigenius, or mammoth, have a bolder and more extensive curvature than those of the Elephas indicus. Some have been found which describe a circle, but the curve being oblique they thus clear the head, and point outwards, downwards, and backwards. The numerous fossil tusks of the mammoth which have been discovered and recorded may be ranged under two averages of size-the larger ones at nine feet and a-half, the smaller at five feet and a-half in length. I have elsewhere* assigned reasons for the probability of the latter belonging to the female mammoth, which must accordingly have differed from the existing elephant of India, and have more resembled that of Africa in the development of her tusks; yet manifesting an intermediate character by their smaller size. Of the tusks which are referable to the male mammoth one from the newer tertiary deposits in Essex measured nine feet ten inches along the outer curve, and two feet five inches in circumference at its thickest part; another, from Eschscholtz Bay, was nine feet two inches in length, and two feet one and a-half inches in circumference, and weighed one hundred and sixty pounds. I have also measured a specimen, dug up off Dungeness, which measured eleven feet in length. In several of the instances of mammoths' tusks from British strata the ivory has been so little altered as to be fit for the purposes of manufacture; and the tusks of the mammoth, which are still better preserved in the frozen drift of Siberia, have long been collected as articles of commerce. In a specimen of the extinct Indian elephant (Elephas ganesa, F. and C.), preserved in the British Museum, the tusks are ten feet six inches in length, and in consequence of their small amount of curvature, they project | eight feet five inches in front of the head; their apparent disproportion to the size of the skull is truly extraordinary, and exemplifies the maximisation of dental development. In the account of the mammoth bones and teeth of Siberia, published in the "Philosophical Transactions for 1737 (No. 446), tusks are cited which weighed two hundred pounds each, and "are used as ivory to make combs, boxes, and such other things; being a little more brittle, and easily turning yellow by weather and heat." From that time to the present, there has been little intermission in the supply of ivory furnished by the tusks of the extinct elephant of a former world. Cuviert states, that the elephant of Africa, at least in certain localities, has large tusks in both sexes, and that the female of this species, which lived seventeen years in the menagerie of Louis XIV., had larger tusks than those in any Indian elephant, male or female, of the same size which he had seen. The ivory of the tusks of the African elephant is most esteemed by the manufacturer for its density and whiteness. It has a semi-transparent aspect when recently fractured. and are generally a little expanded at the middle; and they are more numerous in proportion to the size of the crown than in the existing species of Asiatic elephant. In the African elephant, on the other hand, the lamellar divisions of the crown are fewer and thicker, and they expand more uniformly from the margin to the centre, yielding a lozenge-form when cut or worn transversely, as in mastication. The horizontal as well as vertical course of development of the elephant's grinder is well illustrated by the molar, the last of the lower jaw. The separate digital processes of the posterior plates are still distinct, and adhere only by the remaining cement; a little in advance they are united, to form the transverse plate; and, at the opposite extremity of the tooth, the common base of dentine is exposed by which the plates are finally blended into one individual complex grinder;* this never takes place simultaneously along the whole extent of the tooth in the Indian elephant. The African species manifests a closer affinity to the mastodon by the basal confluence of the plates before the anterior ones are worn out. The formation of each grinder begins with the summits of the anterior plate, and the rest are completed in succession. The tooth is gradually advanced in position as its growth proceeds; and in the existing Indian elephant, the anterior plates are brought into use before the posterior ones are formed. When the complex molar cuts the gum, the cement is first rubbed off the digital summits; then their enamel cap is worn away, and the central dentine comes into play with a prominent enamel ring. The digital processes are next ground down to their common united base, and a transverse tract of dentine, with its wavy border of enamel, is exposed. Finally, the transverse plates themselves are abraded to their common base of dentine, and a smooth and polished tract of that substance is produced. From this basis the roots of the molar are developed, and increase in length to keep the worn crown on the grinding level, until the reproductive force is exhausted. When the whole extent of a grinder has successively come into play, its last part is reduced to a long fang, supporting a smooth and polished field of dentine, with, perhaps, a few remnants of the bottom of the enamel folds at its hinder part. When the complete molar has been thus worn down to an uniform surface, it becomes useless as an instrument for grinding the coarse vegetable substances on which the elephant subsists. It is attacked by the absorbent action, and the wasted portion of the molar is finally shed. The grinding teeth of the elephant progressively increase in size and in the number of lamellar divisions from the first to the last. The molar teeth of the elephant are remarkable for their great size, even in relation to the bulk of the animal, and for the extreme complexity of their structure. I cannot omit, therefore, some notice of those teeth in the present discourse. The crown, of which a great proportion is buried in the socket, and very little more than the grind- There are few examples of organs that manifest a ing surface appears above the gum, is deeply divided more striking adaptation of a highly complex and beauinto a number of transverse perpendicular plates, consist-tiful structure to the exigences of the animal endowed ing each of a body of dentine coated by a layer of with it, than the grinding teeth of the elephant. We enamel and this, again, by the less dense bone-like perceive, for example, that the jaw is not encumbered substance which fills the interspace of the enamelled with the whole weight of the massive tooth at once, but plates, and here more especially merits the name of that it is formed by degrees as it is required; the division cement," since it binds together the several divisions of of the crown into a number of successive plates, and the the crown before they are fully formed and united by subdivision of these into cylindrical processes, presenting the confluence of their bases into a common body of the conditions most favourable to progressive formation. dentine. But a more important advantage is gained by this sub As the growth of each plate begins at the summit, they remain detached, and like so many separate teeth, or denticules, until their base is completed, when it becomes blended with the bases of contiguous plates to form the common body of the crown of the complex tooth from which the roots are next developed. The plates of the molar teeth of the Siberian mammoth (elephas primigenius), are thinner in proportion to their breadth, * " History of British Fossil Mammals," Vol. viii., p. 247. Loc. cit., p. 55. * Some anatomists have described the divisions of the crown of the elephant's grinder as so many "distinct teeth," and Mr. Corse (Loc. cit., p. 213), who first propounded this view, calls each complex grinder "a case of teeth," and states "that these teeth are merely joined to each other by an intermediate softer substance acting like cement." But this statement applies only to the incompletely-formed tooth; and the detached eminences of each individual plate or of the crown of any complete tooth, at that stage of growth when they are held together only by the still uncalcified supporting matrix, might reasonably be regarded as so many distinct teeth. |