lATAKKII. 



CATECHINUM. 



All the operations for cataract may be classed under three heads, a* 

 they are calculated to effect, either its extraction ; its displacement 

 from the axis of vision ; or its absorption or solution. 



Extraction is commonly effected in the following manner : A fine 

 triangular knife, sharp at the point and the oblique edge, and having 

 the back in a straight line with the handle, and the flat of the blade 

 towards the eye, is steadily and quickly passed through the upper or 

 lower half of the cornea, as near to the iris as possible without touching 

 it. A needle slightly curved at the point is insinuated under the flap 

 thus formed, and brought to bear upon the front of the capsule so as 

 to lacerate it ; upon gentle pressure of the globe the lens slips out of 

 the capsule, and easily distending the pupil escapes through the wound 

 in the cornea, which soon heals in favourable cases, and the sight is 

 restored. Spectacles suitably convex must afterwards be worn as a 

 compensation for the refractive power of the lens. This operation is 

 chiefly suited to the hard cataract and the adult age. It is inexpedient 

 in gouty and inflammable subjects, and when the eye is either too 

 prominent or too deep in the orbit. 



Displacement of the lens from the axis of vision, which was the 

 method practised by the ancients, is effected in several ways ; the most 

 usual is that called depression or cmtc/iimj (from the French couchtr, to 

 lay down). A sharp needle, with edges which cut a little way from 

 the point, is introduced perpendicularly through the sclerotic, near its 

 junction with the cornea, and consequently behind the lens ; the pupil 

 having been previously dilated by belladonna. The point is then 

 brought forward through the lens, which, by a backward and down- 

 ward movement of the hand, is drawn out of its place behind the 

 pupil, and lodged under it in the vitreous humour. The opaque body 

 being thus removed, the sight immediately returns ; but as the lens 

 may partially rise again into its place, it is often necessary to repeat 

 the operation at intervals, which has been done a dozen times with 

 perfect eventual success. The lens does not produce so much irrita- 

 tion in its new situation as might naturally be expected, and it is 

 commonly absorbed in part or wholly in the course of time. This 

 method of operating is not very frequently resorted to in the present 



The 



he third kind of operation, which is intended to cause the absorp- 

 tion of the lens, or its solution in the aqueous humour, is performed 

 much in the same way ; but instead of drawing the needle backward, 

 the operator pushes it in through the lens into the pupil, and lacerates 

 the anterior capsule. The aqueous humour is thus admitted to act 

 upon the cataract, which, perhaps, after several repetitions of the 

 operation, becomes absorbed or dissolved, and vision is thus restored. 

 This mode of operating, with variations which need not be detailed, is 

 generally adopted in soft cataract, and always in congenital cases. 



It is not only necessary that much discretion should be exercised in 

 the choice and execution of the operation ; it must in all cases, more 

 especially in extraction, be preceded and followed by means calculated 

 to prevent inflammation, which often occurs in spite of all precautions, 

 and may render the operation worse than useless. It is not usually 

 thought expedient to operate on one eye while useful vision remains 

 in the other ; nor by the method of extraction in both eyes at the 

 same time : nor is an operation warrantable when the patient cannot 

 distinguish light from darkness, which proves that some other cause 

 of blindness exists independently of cataract ; nor if the iris or other 

 membranes in front of the crystalline be disorganised by previous 

 inflammation. Many other cases might be enumerated in which an 

 operation is of questionable propriety. On the whole, however, cata- 

 ract may thus be cured, and useful or even perfect vision restored in a 

 large proportion of cases. The pain of the operation itself is very 

 inconsiderable, nor does any disfigurement or inconvenience arise if it 

 be skilfully performed. 



CATARRH, or COKY'ZA, that is, catarrh in the strict sense of the 

 term, commonly called cold, consists of inflammation of that portion of 

 the mucous membrane of the air passages which lines the nostrils. 

 Inflammation, though often strictly confined to this portion of the 

 lining membrane, when it gives rise to the symptoms known under the 

 name of common cold, or coryza, is very apt to extend beyond the 

 nostrils, when it produces other diseases which are distinguished by 

 different names : when, for example, the inflammation extends from 

 the nostrils into the frontal sinuses, pain, and a sense of weight in the 

 head being superadded to the symptoms of coryza, the aflV 

 called gravedo, catarrhs! headache, or cold in the brawl; when inflam- 

 mation extends to the back part of the throat, the affection is called 

 cynancbe caUrrbalis, or catarrhal sorethroat; when to the larynx, 

 laryngitis ; and when to the bronchi, bronchitis. [BROHCHITIS.] 



The symptom* of coryza are a sense of uneasiness, fulness, heat, and 

 stuffing in the nostril*, frequent sneezing, diminished ncuteness or 

 total loss of the sense of smell, together with a slight impediment to 

 the respiration, occasioned by the impeded transmission of 

 through the nostrils to the lungs, in consequence of the swelling of the 

 membrane, the degree of the swelling being always in propr.i' 

 the severity of the inflammation. [BRONCHITIS.] Though the main 

 seat of inflammation in coryza is always in the lining membrane of the 

 nostrils.vet very constantly a sufficient degree of it extend* to the 

 frontal sinuses to occasion some uneasiness there, inducing a sense of 

 fulness, heat, weight, and even pain across the forehead. Occasionally, 

 too, the membrane which lines the tube through which the tears pass 



into the nose becomes so much swollen that the tears cannot enter it, 

 and consequently flow over the cheek ; while the external membrane 

 which is reflected over the eye itself participates in the inflammatory 

 affection, and becomes reddened and painful. 



These local disorders are often the only symptoms which exist : l>ut 

 whenever the disease is severe, the system becomes affected, and then 

 to these local symptoms are superadded indications of a general dis- 

 turbance in the economy. These general disordered functions are 

 uniformly those which indicate a feverish condition of the system, 

 namely, chilliness or coldness succeeded by heat, dryneas of the skin, 

 lassitude, stiffness, or a sense of uneasiness, often amounting to pain, 

 in the back and limbs, together with a greater or less degree of 

 headache. 



The dryness of the membrane affected, in coryza, the first conse- 

 quence of inflammation, from the suppression of secretion, gives rise to 

 the irritation, the itching, and the sensation of heat in the nostrils, 

 and more particularly at their entrance. Next comes the acrid fluid 

 already described [BRONCHITIS] , which flowing upon the upper lip and 

 the anterior portion of the nostrils, irritates and excoriates them, and 

 which, passing by the posterior nares into the pharynx, and thence 

 upon the epiglottis and glottis, occasions violent cough ; and last of all 

 flows the bland fluid, with the immediate subsidence of all irritation. 

 [BRONCHITIS.] The causes of coryza are precisely the same as those of 

 bronchitis. 



Of all the diseases to which the human body is subject, catarrh is 

 the most frequent, at least in this climate, which is subject to such 

 sudden and great changes of temperature, and where the atmosphere is 

 so often loaded with moisture. Scarcely an individual passes through 

 the year without suffering from it in a greater or less degree. Fortu- 

 nately its danger is by no means proportionate to its frequency. It is 

 never of itself fatal excepting in the very young and in the very old. 

 But inflammation of the mucous membrane of the nostrils, however 

 slight it may be at first, is very apt to spread to other portions of the 

 membrane, to become severe, and consequently to occasion serious 

 disease. It is the constant source of bronchitis, it often terminates in 

 inflammation of the substance of the lung, and it frequently lays the 

 foundation for consumption. Hence whenever there is the slightest 

 appreciable predisposition to disease of the lung, a common cold, in 

 however mild a form it may come on, ought to be attended to with 

 anxious care. Every year many persons apparently in good health at 

 its commencement are dead before its close, in consequence of two or 

 three days' neglect of a cold. 



The disease, at first local in its seat, may often be cured at once, or 

 at all events its severity may be lessened and its duration shortened by 

 the application of a local remedy ; such as the inhalation through the 

 nostrils of the vapour of warm water, or what, perhaps, is more. 

 effectual, the vapour of an infusion of chamomile flowers, or of a 

 decoction of poppy-heads. The steam from these heated fluid.- 

 be made to pass through the nostrils for at least the space of a quarter 

 of an hour or twenty minutes at a time. It is important that the 

 temperature of the apartment be maintained uniformly at a moderate 

 degree, about 65, the sleeping as well as the sitting-room. With a 

 view of determining to the skin, so as to produce a general and gentle 

 perspiration, the feet, immediately before going to bed, may be bathed 

 for twenty minutes in warm water, and the bed warmed. A tumbler 

 full of wine-whey, or a basin of warm gruel, will promote the perspira- 

 tion, and under this simple treatment the patient will often arise in the 

 morning without the slightest remains of the disease. A mild aperient 

 may be often added with advantage. 



When there is any degree of fever, the treatment must be the same 

 as in bronchitis. 



CATCH, in music, a composition of the humorous kind for three 

 or four voices, which owes its origin to this country, and does not 

 appear ever to have travelled out of it. It is a song of as many verses or 

 couplets as parts. The highest part is first sung through alone ; the 

 singer of this goes then to the second part, tin second "ice takes the 

 first, Ac., and thus each performer sings through all the parts in 

 succession, and, generally, three times over. The mis on 



the distribution of the wonls among the jH'rformers. This is so con- 

 trived that a meaning is given to the lines wholly different from that 

 which appears when they are read in a straightforward manner. 'Ph.- 

 catch in "the good old times" was often obscene and disgusting. 

 Among other improvements in manners the abolition of such oil. 

 productions deserves to be mentioned here. Some good catches, how- 

 ever, luit of later date, by Webbe, Callcott, Ac., remain, which are 

 exceedingly facetious, and such as may be, and are, introduced at any 

 i.-eting with propriety. 



CATK.rn' [NOENIC \< II. ,< -Jl a O ) is that portion 



of catechu which in insoluble in cold water. It is soluble in hot water, 

 ami crystallises in tile form of a white silky powder. When heated 

 with caustic potash it yields a black acid, called japonic arid (C lt H.O c ). 

 Carbonate of potash produces with it mijinic acid, or rufocatcchadc 

 acid (C.,H.O,|. whi< -h has a red colour. [TAKVIC A< 



CATKCHI'M'M, Medical impertia of. This peculiar principle is 

 obtain. >y from catechu, strictly so called, but also from 



gamUrand some kinds of cinchona bark. Certain slight differences 

 are found in it, according to the source whence it has been obtained, 

 such as that from catechu having no acid reaction on litmus, while the 



