530 THE TREATMENT OF DISEASES. 



there is simply a greater sensitiveness of the surface to the impression of cold, so 

 that a current of cool air, or the contact of a cold body, produces a feeling of 

 chilliness which runs momentarily through the frame, and then subsides. The sense 

 of cold, however, is usually more permanent, and quite independent of surrounding 

 objects. It begins most commonly in the back, and extends to the limbs and over 

 the body, producing chattering of the teeth, and sometimes universal tremor and 

 shaking, and this may occur although the patient may be near the fire, or 

 covered with blankets in bed. In some fevers the rigors are more intense, and of 

 far more constant occurrence than in others. In small-pox they are definite and 

 prolonged, and in typhus fever they are frequently well marked. In scarlet fever, 

 diphtheria, measles, and acute dysentery, there may be a distinct rigor or only a 

 passing sensation of chilliness. Typhoid fever usually commences insidiously, but 

 in the cases in which the onset is sudden, a shivering fit is not of unfrequent occur- 

 rence. The cold stage of ague may be said to be composed of a succession of rigors. 

 It is not improbable that shivering fits are induced more readily in some constitutions 

 than in others. The mere snipping of a blister, an operation which it is needless to 

 say is perfectly painless, will, in many people so far throw the nervous system off its 

 balance, as to produce a rigor. Some individuals are so delicately organised that 

 they can never pass water in the open air without experiencing a transitory 

 feeling of chilliness. 



It is often said that the rigor announces the entrance of the poison into the system, 

 but this is obviously incorrect ; for example, a person is brought in contact with 

 a patient suffering from small-pox, but it is not till twelve or thirteen days after 

 that he has a rigor, and the disease declares itself. 



It would be no easy matter to persuade the patient that at the very time the 

 rigor is at its height, and he is shivering with cold, his temperature is above the 

 normal, and his body much hotter than it has been for weeks and months past, 

 and yet such is the case. In children the place of the rigor is often taken by a 

 convulsion. A convulsion not unnaturally causes considerable alarm and anxiety 

 to the friends and relatives, but it should always be remembered that in the case 

 of children it, at the commencement of an acute illness, means no more than does 

 a shivering fit in an adult. 



First and foremost among the conditions which indicate the existence of fever 

 is an elevation of temperature. Without increased heat of the body fever cannot 

 exist ; elevation of temperature is the essence of fever. Formerly we judged of 

 the temperature of the body by the hand, now, by means of the thermometer, we 

 are enabled to estimate it accurately, and record it numerically. We used to speak 

 of a patient being a "little feverish," or perhaps of his having a "high fever," but 

 now we prefer to say that he has a temperature of 100 or 105, or whatever it 

 may be. The temperature is often of the greatest service in enabling us to determine 

 the nature of the fever from which the patient is suffering, or, this being known, 

 to detect the existence of complications or other changes in the patient's condition. 

 In some acute diseases the range of temperature is very characteristic. Thus, in 

 the different varieties of ague, the temperature suddenly and speedily rises to 

 105 or 106 Fahr., and then with equal rapidity returns to the normal, there 



