42 DISEASES OF CHILDREN. 



should also remember that, though they may be incapable of suffering themselves, 

 they may readily cany the disease to others. We shall reserve further remarks on 

 the contagion until after our discussion of the disease itself, when we shall be better 

 able to explain whence the contagious matter comes. A person having been 

 exposed to contagion, a contagious particle having, as it were, been sown in his body, 

 a certain period elapses before the disease becomes manifest. This is called the 

 period of incubation, and in scarlet fever it is a very variable period, its length 

 seeming to depend not only upon the recipient but on the giver of the poison also. 

 We often observe that, in the same soil and under the same condition, some seeds 

 germinate sooner than others ; and it is a very common observation that variations 

 of soil, temperature, etc., are capable of causing great variation in the time which 

 elapses between the sowing of the seed and the first appearance of the shoots. This 

 incubative period in scarlet fever seems to vary between twenty-four hours and 

 a week, and some say that as much as a fortnight sometimes elapses between 

 the exposure to the fever poison, and the development of the disease. 



The symptoms and severity of scarlet fever vary immensely. They may be 

 so mild as scarcely to be perceptible, and may be so severe that death ensues within 

 twenty-four hours of their first appearance. We shall first of all describe an attack 

 of ordinary severity. 



The child complains of " feeling out of sorts ; " the appetite fails, and symptoms 

 of feverishness make their appearance. There are chills alternating with flushings 

 and a sense of heat. Headache is complained of, and very often vomiting is one of 

 the first symptoms to attract attention. The pulse is quick, and if the temperature 

 be taken it will be found considerably elevated. It may rise as high as 104 degrees 

 on the first day, or nearly six degrees above the normal temperature of health. The 

 next symptom to attract attention is the sore throat ; and if the throat be looked at, 

 the tonsils will be seen to be enlarged, and there is a general redness and swelling of 

 the whole of the back of the throat. The tongue also presents a characteristic 

 appearance. It is generally somewhat furred, and at its tip a number of fine red 

 points will be seen showing through the white fur, giving the end of the tongue 

 an appearance very like that of a strawberry, so that the " strawberry tongue " 

 of scarlet fever has become one of the recognised terms of medicine. The reader 

 must be warned, however, that this condition of tongue is common in other 

 states besides scarlet fever, and it is impossible to distinguish scarlet fever by 

 the appearance of the tongue alone, unless the other symptoms be present also. 

 With these symptoms there is often some sensation of heat about the skin, and 

 if the patient be asked to clench the hand, it will often occasion feeling of 

 tension. Sometimes within twelve hours, and always before the lapse of forty-eight 

 hours, after the first symptoms, the characteristic rash of scarlet fever appears. It 

 appears first at the root of the neck and upper part of the chest. It consists 

 of a number of fine scarlet points, and the skin looks sometimes as if it had been 

 covered with a bright scarlet powder. These points may coalesce in places, and then 

 we get scarlet patches. The colour varies, and may be of any shade of red ; or occa- 

 sionally the eruption is dusky in appearance. When the skin is pressed upon with the 

 point of the finger, or put upon the stretch, the colour of the points fades. The rash 



