TK.r.rii OK WHKKI.S. 



01 



these symptoms come an prematurely. The great resource and com- 

 fort of the sufferer in UMM oases is the introduction of artificial teeth. 

 The manufacture of UMM organ* hu ben carried to such perfection 

 that little <>r >! inconvenience U felt from their presence in the mouth, 

 whilit they perform the functions of mastication and giro the necessary 

 modulation to the voice at though they were the original teeth. They 

 have even thU advantage over natural teeth, that they never ache. 



Ji,im"rrh</r from the periosteum of the alveoli is not unfrequently 

 a source of alarm, and nassi are recorded in which death baa occurred 

 from this caiue. It usually cornea on after the extraction of a tooth. 

 Under ordinary ciru instances the socket becomes filled with a coagulum 

 of blood, which arrests all further bleeding ; but in these eison the 

 blood continues to be poured out from the wounded vessels, and resists 

 all attempt* at arrest. The best method of treating these esses is to 

 plug the socket with a piece nf lint dipped in some strong styptic. One 

 of toe most efficient styptics for these cases is the matico, which should 

 be powdered and applied ou the outaide of a plug of moistened lint. 



Iftammatiuu af Ike (into. This may be either acute or chronic, 

 and may come on independent of caries of the tooth or other disease. 

 Acute inflammation is most frequently seen u the result of taking 

 mercury. [MERITHT, Mnlifil Proprrtiet of.] Chronic inflammation 

 attended with ulceration of the gums is very frequent It may arise 

 from di-f**~< conditions of the teeth, or from a disordered state of the 

 system. In inflammation without ulceration stimulant applications 

 are very beneficial, whilst the ulcer* may be touched with nitric acid, 

 or painted with a strong solution of chlorate of potash. 



Illnr dm*. When lead is introduced into the system in small quan- 

 tities for a length of time, its presence in the system it indicated by a 

 blue or purplish line running along the edges of the gums just where 

 they meet the teeth. This curious fact, which was first pointed out 

 by Dr. Burton, has since been confirmed in a large number of cases. 

 The blue line U, however, only seen in cases where tartar has accumu- 

 lated on the teeth. It is not seen in cases either where there are no 

 teeth in the gums. Wherever present it indicates the action of lead 

 on the system, and should lead to the investigation of the circum- 

 stances under which the patient has received this substance into the 

 system. Mr. Tomes hu mentioned two cases in which the same kind 

 of discoloration has taken place from the action of mercury on the 

 system. It is not, however, impossible that the preparations of mer- 

 cury taken in these cases contained lead. 



Tartar. The saliva which is poured into the mouth contains cer- 

 tain earthy matters in solution, which are precipitated on the roots of 

 the teeth at the point where they are covered by the gums. This pro- 

 ci|'iutc, which is a true salivary calculus, is called " tartar." Win n 

 chemically examined it has been found to contain in 100 parts 



Eirthv ptuwphatei 

 Saltrarjr mucus 

 rtralia . 

 Auiaul matter 



79-0 



1S-5 



1-0 



7-3 



100-0 



It assumes a variety of colours on the teeth, according to the nature 

 of the food habitually taken. The accumulation of this substance on 

 the teeth tends to produce inflammation of the gums and to cause 

 their absorption as well as that of the alveolar processes. 



When tartar has accumulated to a considerable extent it should be 

 sealed off the teeth by means of instrument* fitted for the purpose. 

 : the Rrcot objects of the daily brushing of the teeth is the pre- 

 vention of the accumulation of this tartar. One of the best dentifrices 

 for habitual 11*3 is the camphorated tooth-powder, which consists of 

 camphor carefully powdered and mixed with chalk. All agents that 

 would dissolve the tartar would dissolve the teeth, and must therefi >re 

 be carefully avoided. 



(Tomes, Leetura on D.ndil l'!iy>i<J my ; Tomes, Manual of ! 



<.) 



I'M or WHKKI.S. 



TKKuUKTIS <C,H.f). A native crystalline resin found in the 

 peat of Denmark. 



TELEGRAPH (from T*U, "distant," and ypAfu, "write"), a 

 *' or process for communicating intelligence to a distance, 

 uuallv by means of preconcerted signals, to which some conventional 



' : 



meaning u attached. The i 



' (from ffijua, " a sign," and 



',., "bear"), was also applied to some of the machines used for 

 fleeting telegraphic communication; which, in an extended 



may U considered to embrace every meant of conveying intelligence 

 bjr gestures and visible signals, as flags, lanterns, rockcU, blue-lights, 

 beacon fires, Ac., or by audible signals, as the firing of guns, the Mow- 

 ing of trumpets, the beating of drums or gongs, 4c., as well as !.. the 



specially provided for the purpose. 

 Although telegraphic communication, as a means of conveying any 

 required mtelbgrnc*. is an invention of recent date, the use of signals 

 for the speedy transmission of such brief messages as might be pre- 

 viously arranged between persons, is a practice derived from the most 



a means ol 

 in alluded to by 

 tries before the 

 Christian era, and who worm the Uenjamitc* to " set np a sign of fire 



moot* antiquity. The use of bcacun-fires, for example, as i 

 giving speedy warning of toe approach of an enemy, U allu 

 the prophet Jeremiah, who wmte about six centuries I 



in Beth-haccerem ; for evil," he adds, " appeareth out of the north, 

 and great destruction." (Jeremiah, vi. 1.) The fine description given 

 by .schylus, in his ' Agamemnon,' of the application of a fine of fire- 

 signals to communicate the intelligence of the fall of Troy, in often 

 referred to as an early instance of this kind of telegraphic deepatch. 

 This simple means of spreading an alarm, or communicating intelli- 

 gence, is described by Scott in the ' Lay of the Lut Minstrel ; ' and in 

 a note he refers to an Act of the Scottish parliament in 1455, c. 48, 

 which directs that one bale or faggot shall be warning of the approach 

 of the English in any manner ; two bales, that they are cootiny 

 .in 1 i '.ir bales blazing beside each other, that the enemy are in great 

 force. Such signals, though best adapted to give information by nk-Iit , 

 were also available in the daytime, when they appeared as columns of 

 dense smoke. Torches held in the hand and moved in any particular 

 manner, or alternately displayed and bidden behind a screen, were also 

 used in ancient times as signals Polybiua describes two somewhat 

 complicated methods of telegraphing by means of torches; and I'. 

 WUkfaw, in his curious work entitled 'Mercury; or the Seer. 

 Swift Messenger,' after describing this telegraph "f IVilyliius. mentions 

 another which requires only three lights or torches to indicate the 

 lour necessary letters of the alphabet, which are, according to 

 this plan, which he gives on the authority of Joachiuius Portius, to be 

 diviili 1 into three classes of eight letters each. The first class is 

 represented by one torch, the second by two, and Uie third by three ; 

 and the number of the letter by the number of limes which the 

 torches are elevated or discovered. Similar to this, is the ni'.-ht- 

 telegraph contrived by the Kev. James Bremner, of tl 

 Islands, and rewarded by the Society of Arts in 1816. (' Soc. Trans., 

 xxxiv.) A single light constitutes the whole apparatus, and the 

 whole operation consists in its alternate exhibition and concealment. 

 This plan hod been found suitable for distances of twenty miles and 

 upwards, and had been successfully put in operation between the 

 lighthouse on Copeland Island and 1'ort Patrick on the opposite side 

 of the Irish Channel. Bishop Wilkins also describes a method which 

 depends upon the relative positions of two lights attached to long 

 poles, and which, he says, " for its quickness and speed is much to be 

 preferred before any of the rest." This plan came very near to the 

 principle upon 'which some of the subsequent telegraphic systems 

 depended. In suggesting the use of extended lines of telegraphic 

 communication, he further hints at the application of the telescope 

 (or, as he styles it, ' Galileus his perspective '), to the deciphering of 

 distant signals. 



Other writers, such as Kircher, Schottus, and Kessler, have pub- 

 lished plans for telegraphic signals. Keuler proposed to cut out such 

 characters as it was desired to show in the ends of a cask, which was 

 to be elevated with a light enclosed in it. The Marquess of \Vo 

 also, in his 'Century of Inventions,' 1663, announce*, "How at a 

 v. in. l,.w, as far as the eye can discover black from white, a man may 

 hold discourse with his correspondent, without noUe made or notice 

 taken," &c. ; and again, " A way to do it by night as well as by day, 

 though as dark as pitch U black." But the e.irlie-t well -.letmed plan 

 of telegraphic communication appears to be that described in a p;iprr 

 addressed to the Royal Sm-iety in 1684, by Dr. Robert Hooke. ,inil 

 published in 1726 in Dei-ham's collection of his ' PhfloeopUoaj Ex- 

 periment* and Observations,' pp. 142-150, "showing a way how to 

 communicate one's mind at great distances." Hooke's scheme will 

 be understood by referring to fy. 1, which represents an el' 



Fig. 1. 



H 



T+X3CZHD 



TTVAXVAO 



OXC 



frame-work supporting a panel or screen, a, behind which were to be 

 suspended a number of symbols or devices, formed of deal plank, of 

 the various shapes represented by the small black figures. The first 

 twenty-four of them*, which consist entirely of >n.:i^ht lines, were to 

 .-t.ind for alphabetic characters ; and the six devices consisting of 



! lines were to be used as arbitrary signals. Whenever it was 

 desired to display any of these characters, they were to be drawn from 

 behind the screen by a rope r, passing over pulleys in the frame-work, 

 and so n n ! -re.l \i-ilile in the open space at 6. These telegraphs were 

 to be erected upon elevated stations, and telescopes were to bo used by 

 the observers. The order of connection between the sign- employed 

 ami the letters of the alphabet might, it U explained, be infinitely 

 varied, for the sake of secrecy; and none of the parties employed, 



ng those at the terminal stations, need have any knowledge of 



mage communicated. Hooke further proposed a scheme for 



night communication by uj-.-nns of lights disposed in a certain order 



