329 



SCARIFIER, 



SCARLATINA. 



330 



of a scarf, owing to the effect of the shrinking of the timber, and the 

 liability of the bolts to be, in consequence of their small dimensions, 

 pressed into the wood. fig. 4 is a scarf that may be used without 



S . 4. 



bolts, although the addition of them adds much to the security of the 

 joint. In this plan a key or wedge is driven gently into the square 

 space at a, to bring the parts into their places. Two other illustra- 

 tions will suffice to explain other varieties of scarfing. Fig. 5 is a 



Fig. 5. 



diagonal scarf, in which the parts are said to be tabled together ; they 

 being so cut and fitted to each other that no force can separate them 

 longitudinally, without breaking, so long a? the bolts hold them 

 together sideways, fig. 6 shows a very simple and good plan of 



Fig. 6. 



~v^~ 



y executed with ace n nicy, c>\\ 



of oblique faces. In this arrangement keys are used to resist any force 

 tending to separate the beam in the direction of its fibres, instead of 

 the parts being tabled together. The ends of the keys, which should 

 bj of hard wood, and let into both pieces of the beam to an equal 

 d ptli, are shown by the dark tint in the cut. 



Varieties may be almost infinitely multiplied by increasing the 

 number of the faces, whether oblique or square, and uniting the parts 

 cither by tabling, keying, or a combination of the two ; but in most 

 cases the greatest simplicity should be aimed at, in order that the 

 I>arts may the more readily be made to fit each other with accuracy. 

 Very complicated scarfs have been used by some old carpenters, 

 respecting which Robison observes that " many seem to aim at making 

 the beam stronger than if it were of one piece ; " an absurdity too 

 manifest to need refutation. Where a scarfed beam is exposed to 

 transverse strains, the joint should be varied from the ordinary form ; 

 but for these and some other contrivances to meet peculiar circum- 

 stances the reader is referred to the practical works of Tredgold, 

 Nicholson, &<'. When a piece of timber subject to compression in the 

 direction of its length has to be scarfed, oblique faces should be 

 avoided, because of their tendency to slide upon each other. Though 

 bolts are commonly used to secure scarfed joints, iron hoops or straps, 

 driven on tightly, have been recommended in their stead, and possess 

 the advantage of not weakening the timber. In joints that depend 

 wholly on bolts, Tredgold recommends that the sum of their areas 

 should never be less than two-tenths of the area of the section of the 

 beam. From the same authority we give the following rules for the 

 length of scarfs : 



In oak, ash, or elm, the whole length of the scarf should be six 

 times the depth or thickness of the beam, where there arc no bolts. 



In fir, without bolts, twelve times the depth. 



The whole length of a scarf dependent wholly upon bolts should be 

 in oak, ash, or elm, about three, and in fir, six tunes the depth of the 

 1 1 iui. 



When bolts and indents are used together, the length of the scarf 

 may be, in bard woods, twice, and in soft woods four times the depth. 

 -. IJIKIKK. [ARABLK LAND.] 



SCARLATINA (originally written Scarlattina, from scarlatta, a 

 red-coloured cloth), Scarlet fever. This disease was not distinguished 

 by the ancients from any of the other eruptive fevers ; they contented 

 themselves with classing together all these fevers as pestilential, and 

 they attributed the variety of eruptions that accompanied them to 

 different combinations of the humours. Small-pox, measles, and 

 scarlatina were described by the Arabians, but they looked upon them 

 merely as varieties of the same disease, and even to the close of the 

 18th century the two last-named maladies were confounded. Dr. 

 Withering, in a second edition of an essay which he published 

 on scarlet fever, in the year 1793,Jir8t pointed out its distinctive 

 characters. 



Scarlatina, like small-pox and measles, may appear as an epidemic, 

 or it may be propagated by a specific contagion ; as an epidemic, it 

 most usually appears at the latter end of the summer and the beginning 

 of autumn; sporadically, it is met with at all seasons; it further 

 resembles the diseases we have just named in rarely attacking twice 

 the same individual. Scarlatina varies much in severity, from the 

 mil'l febrile disturbance which has been pronounced by Sydenham to 



be fatal only through the officiousness of the doctor, to that grave 

 form of the disease which has received the appellation of malignant. 

 This difference has given rise to its division into three species, the 

 Scarlatina simplex, S. anginosa, and S. maligna. Scarlatina is ushered 

 in by rigors, followed by increased heat of the body, thirst, loss of 

 appetite, and all the symptoms of inflammatory fever. On the second 

 day of this fever, or somewhat later in the severer forms of the disease, 

 patches of a scarlet-coloured efflorescence begin to appear on the face 

 and neck, which extend downwards, and, coalescing, soon spread over 

 the whole body. On the trunk, however, the rash is seldom uniform, 

 but is distributed into diffuse irregular patches, the scarlet hue being 

 most vivid about the flexures of the joints and on the loins ; occa- 

 sionally minute vesicles are visible, and Sauvages has considered this 

 circumstance sufficient to constitute a distinct species, which he calls 

 S. rariolodet. On the third and fourth days the eruption is at its 

 height ; even the mouth and fauces are not free from it, the 

 papillae of the tongue are unusually red and elongated, and the face is 

 generally more or less swollen. On the fifth day it begins to decline, 

 disappearing by interstices, so that the patches reappear as at the com- 

 mencement, and it is generally gone before the end of the seventh. 

 Between the eighth and twelfth days the cuticle comes off in the form 

 of a scurfy desquamatiou, and the fever has subsided. This is the 

 course of Scarlatina simplex. At those periods of the disease when 

 the eruption is in patches, scarlatina is apt to be mistaken for measles, 

 but it may readily be distinguished from the last-named disease by 

 the following signs : In measles, the patches are of a rosy hue, of a 

 cresceutic form, and elevated above the surrounding skin ; in scarlatina 

 they resemble more the colour of boiled lobster, want the crescentic 

 shape, and the hand passed over them detects minute asperities, but 

 no elevated patches. It is further distinguished from measles by the 

 greater heat of skin, the temperature being sometimes as high as 108 

 or 112" of Fahr., by the absence of catarrhal symptoms, and by the 

 state of the papillae of the tongue. 



Roseola is the name of an affection which is characterised by an 

 eruption bearing some resemblance to scarlatina ; but it is of a more 

 crimson colour, pursues its course in a direction contrary to that of 

 scarlatina, namely, from the extremities and trunk to the neck and 

 face, and is attended with less constitutional disturbance. 



Scarlatina accompanied with sore throat *S. anyinona, or cynanchica, 

 as it is termed is a much more frequent and severe form of the 

 disease than that which we have just described. Not only are the 

 precursory febrile symptoms more violent, but the whole course of the 

 malady is protracted ; the eruption is seldom so universal as in 

 the simple variety, but is in scattered patches, which frequently vanish 

 and reappear ; the interior of the mouth and fauces is of a high red 

 colour, tumefied and painful ; superficial ulcerations not unfrequently 

 form on the tonsils, uvula, and soft palate ; and the throat is much 

 clogged up with a tough viscid phlegm. In ij. malujna the fever is of 

 a typhoid character ; the pulse is small and feeble ; the tongue and 

 lips dry, and encrusted with a brown fur ; there is delirium alternating 

 with coma, and the rash is faint and continually coming and going ; 

 the ulcers in the throat are covered with dark-coloured sloughs, and a 

 large quantity of viscid mucus clogs up the fauces and impedes respira- 

 tion and deglutition. These symptoms are often accompanied by 

 diarrhoea, and by petechiie on the skin, with haemorrhage from the 

 nose, throat, bowels, or other parts, which generally lead to a fatal 

 termination : this may occur on the third or fourth day of the disease, 

 or the patient may linger to the second or third week ; if recovery take 

 place, it is exceedingly tedious. It has been observed that during the 

 prevalence of scarlatina adults are not unfrequently affected with, the 

 efflorescence in the mouth and throat, without the skin participating 

 in the affection. For this class of cases Dr. Tweedy has proposed the 

 name of S. faucium. All the varieties of scarlatina that we have 

 mentioned may be observed during the prevalence of the same epi- 

 demic, and even among members of the ame family ; but it is no less 

 true that each epidemic has generally a certain character or type, 

 which it is important to ascertain in order to regulate the treatment. 

 This circumstance renders it difficult to come to any just conclusion as. 

 to the mortality from this disease. 



The reports of the Registrar-General for 1858 and 1859 show the- 

 mortality in London from scarlatina as compared with other forms of 

 zymotic disease : 



Diseases. 1858. 1859. 



Scarlet fever 4118 4197 



Small-pox 247 11.56 



Measles 2383 1305 



Hooping-cough 2700 1741 



Scarlet fever visits certain dutricbi as an epidemic, and that whilst 

 in some years it falls down to a level with other diseases of the same 

 general nature, or even below them, it rises at others far above them. 

 During the years 1857, 58, 59, and 60, scarlet fever has prevailed in 

 London as an epidemic, and has carried off little short of 12,000 

 persons. During these years it has been associated with the disease 

 called diphtheria, but they are distinct diseases and not in any manner 

 produced by the same causes. [DIPHTHERIA.] 



Scarlatina is often followed by other forms of disease. One of the 

 most frequent of these is anasarca, which frequently terminates fatally. 



