B L I 



529 



B L 1 



email sternum, or breast-bone, a shoulder-blade and a cla- 

 vicle (collar-bone) hidden under the skin. 



But these bones are absent in the fourth subgenus, 

 Acontias (Javelin-Snake) of Cuvier : for though this sub- 

 genus resembles the others in the structure of the head and 

 of the eyelicls, there is neither breast-bone, nor shoulder- 

 bone, nor pelvis, but the anterior ribs are united one to the 

 other beneath the trunk by cartilaginous prolongations. 

 Cuvier states that he observed one moderate-sized lung 

 and one very small one. The teeth are small and conical, 

 and Cuvier thinks that he has perceived some on the palate. 

 {See JAVKIJN-SNAKE.] 



To return to our blind-worm, which belongs to the third 

 of these subgenera, and is common throughout Europe. Its 

 length varies from about eleven inches to somewhat more 

 than a foot, and instances have been given of its attaining 

 luore than double that length. The eyes are small (whence 

 one of its names), and the irides are red. The head is 

 small, the teeth are minute and numerous, the neck is 

 slender, and thence the body enlarges, continuing of equal 

 bulk to the tip of the tail, which ends bluntly, and is as long 

 as the trunk, or body part. The scales are very smooth, 

 shining, of a silvered yellow on the upper parts, and dusky 

 beneath : the sides are of a somewhat reddish cast. Down 

 the back extend three black lines, which change with age 

 into different series of black specks, and at length disappear. 

 The general colour of the back may be described as cine- 

 reous, with somewhat of a metallic lustre, and marked with 

 very fine lines of minute black specks. The dusky belly 

 and the reddish sides are marked like the back. 



The blind-worm feeds on earth-worms, insects, &c. ; and 

 the slowness of its motion has obtained for it another of its 

 names. Though perfectly innocuous, it has the character of 

 possessing the most deadly venom, and is persecuted accord- 

 ingly. Pennant quotes Dr. Borlase as assisting this idle 

 and groundless notion, by mentioning a variety of this serpent 

 with a pointed tail, and adding, that he had been informed 

 that a man lost his life by the bite of one in Oxfordshire. 

 Now, if the serpent that bit the man in Oxfordshire had a 

 pointed tail, it could not have been a blind-worm ; and if the 

 story of the death be true, he most probably lost his life by 

 the bile of a black or dusky viper, as Pennant suggests. 

 [See VIPER.] The country people still hold this harmless 

 reptile in utter abhorrence, and wage an exterminating war 

 against it : but the reader may be assured that the ' blind- 

 worm's stinj;' exists only in imagination. The animal ii; 

 very brittle. Laurenti and others assert that, when captured, 

 it throws itself into such rigidity that it sometimes breaks 

 in two. A smart blow with a switch divides it ; and from 

 this fragility Linnaeus gave it the specific name which it 

 still retains. Cuvier is of opinion that the Anguis eri/x of 

 LmiiHMis is only a young blind-worm, which has the dorsal 

 lines well marked, and that the Anguis clivicus, which 

 Daudin makes an Kryjr, is nothing more than an old blind- 

 worm with a truncated tail. The Blind-worm or Slow- 

 ironii of the old English authors, is the Long Cripple of the 

 Cornish, according to Borlase, Ormsla and Koppar-Orm of 

 the Fauna Suecica, L Orvet of Lacepcde, Blindtschleiche of 

 the Germans, Anguis fragilis of Linnaeus. It brings forth 

 its young alive, and it is said twice a year, in the seasons 

 of spring and autumn. ^ 



The author of the article on the Ophidians in Griffith's 

 Cuvier, where much valuable information is to be found, 

 gays that ' by the aid of its muzzle it excavates holes in the 

 earth three or four feet in depth, and conduits describing 

 difl'urent circuits and having several issues.' The same 

 author mentions its concealment of itself during rain and 

 the season of frost, and says that it does not cast its old 

 skin until towards the month of July. The general opinion 

 is (and we think it well founded) that the blind-worm is the 

 Ceecilia of the Latins, and the ru0Xw>(/ and rv^\lvoq of the 

 aiitient Greeks, names given i:' allusion to its supposed 

 blindness, and that it was sometimes called Kw0ie on ac- 

 count of its assumed deafness. Belon considers it to be the 

 serpent called Taphluti, Tephliti, and Tephlini by the mo- 

 dern Greeks. Columella (de Re Rustica, 6. c. 17), following 

 the opinion of its deleterious nature, says that its poison is 

 fatal to oxen, and that the cure is the flesh of storks, because 

 they devour this serpent. Upon the principle, we suppose, of 

 counteracting one poison by the application of another, a The- 

 riaca, or poison-antidote, made from the harmless blind-worms 

 (coeciliit) and the Theriacal water was used as a sudorific 

 gainst the pestilence. But enough of these absurdities. 



BLISTER, a term used to express a bladder or vesicle 

 raised upon the skin by the application of some external 

 irritating substance, and also to denote the external applica- 

 tion itself by which this effect is produced. The term vesi- 

 catory is also frequently given to the external application. 

 The substance usually employed as a vesicatory is the powder 

 of the Spanish fly. [SeepANTHARiDES.] The powder of thfi 

 cantharides is mixed with lard and wax, so as to produce a 

 plaster of tolerably firm consistence, which is spread on 

 leather and applied to the part for the space generally of 

 from ten to twelve hours. The first effect of the appli- 

 cation of the blister-plaster to the external skin is to 

 produce a sense of tingling and heat ; this is followed by 

 redness, commonly attended with pain, and subsequently 

 there takes place an elevation of the cuticle into a vesicle 

 or bladder, which contains a fluid resembling the serum of 

 the blood. On the evacuation of this fluid the redness con- 

 tinues for some time ; the serum gradually thickens, and at 

 last is changed into a whitish curdly substance under which 

 new cuticle is formed, though occasionally the serum is 

 converted into proper purulent matter, the blistered part 

 successively contracting, until the whole wound is healed; 



The effect of the application of a blister is the production 

 of a true inflammation over the whole surface of the skin 

 with which the plaster is in contact. The effusion of a 

 serous fluid from the excited capillary vessels of the skin is 

 one of the ordinary phenomena of inflammation. The 

 formation of the bladder or vesicle is occasioned simply by 

 the elevation of the cuticle from the true 7 skin, by the fluid 

 poured out from the cutaneous capillary vessels. The in- 

 flammation induced by the blister is the effect of a powerful 

 stimulus applied to the cutaneous blood-vessels and nerves: 



The extent of the inflammation is usually confined to 

 the surface in actual contact with the blister; it is com- 

 paratively rare that any degree of irritation is commu- 

 nicated to the general system ; and yet the relief afforded 

 is often so great, that the effect appears disproportioned to 

 the cause, a small external inflammation mitigating or 

 removing an extensive and severe internal inflammation. 

 Much discussion has taken place as to the principle on 

 which this relief is afforded, and the real mode in which 

 tho blister produces the benefit observed to result from 

 it is not clearly understood. It is certain that the chief 

 benefit results in the state of what is termed local inflamma- 

 tion, that is, when the inflammatory action is confined to a 

 single organ or to a part of an organ. In order to under- 

 stand the true nature of the change effected in the part re- 

 lieved, it is obviously necessary to understand the true na- 

 ture of inflammation. [See INFLAMMATION.] It may be 

 here stated that in inflammation artificially induced with 

 a view of observing the phenomena that take place in this 

 process, the blood-vessels of the part inflamed are seen to 

 enlarge and to become preternaturally distended with 

 blood, while the motion of the blood in such vessels is either 

 very much retarded or ceases altogether. The knowledge 

 of this fact enables us to understand, in some measure, the 

 action of a blister. The application of a powerful stimulus, 

 such as that caused by the Spanish fly, in the neighbour* 

 hood of vessels relaxed and over-distended with blood, re- 

 lieves such vessels by depriving them of a portion of their 

 blood, and by consequently removing the state of over-dis- 

 tention. For the stimulus applied to the skin determines a 

 large quantity of blood to the cutaneous vessels under the 

 influence of the vesicatory ; this blood is derived from the 

 blood-vessels of the parts in the immediate neighbourhood 

 of the vesicated skin from the blood-vessels of the inflamed 

 part among the rest ; and the blood-vessels of the inflamed 

 part being relieved from the preternatural quantity of blood 

 that distended them, return to their healthy action. 



Another reason has also been assigned for the relief 

 afforded by the application of blisters. It is observed that 

 when a morbid action exists in any part of the body, it may 

 sometimes be removed by exciting a morbid action of a 

 different kind in the same or in a neighbouring part. It is 

 assumed that two morbid actions of different kinds cannot go 

 on in the same part at the same time ; hence the surgeon and 

 physician, when they observe diseased action going on in a 

 particular part of the body, induce, as near to that part as 

 possible, another action of a different kind, frequently with 

 the effect of lessening or altogether stopping the former 

 morbid action. Now one of the instruments most commonly 

 employed to excite this new action is the blister, and the 

 excitement of such action, on tlie principle just stated, i 



NO. 271. 



[THE PENNY CYCLOPAEDIA.] 



VOL, IV.-3 Y 



