FEVERS. 491 



Hoffmann who has laid the proper foundation of this, and has 

 pointed it out in the most express terms : (Opera, v. i. p. 301.) 

 His words are these : ' Nulla enim ejus species est, sive sit 

 intermittens, sive continua, eaque vel benigna, vel maligna, 

 acuta sive lenta, inflammatoria, sanguinea, aut lymphatica vel 

 biliosa, item cum vel sine exanthematibus, sive denique symp- 

 tomatica, in qua non sub accessione, progressu, immo tempore 

 exacerbationis, partium extimarum refrigeratio, summa cutis 

 ejusque pororum constrictio, vasorum detumescentia, horripi- 

 latio, partium rigor, sudoris suppressio alvique constipatio, ob- 

 serventur.' Here it is asserted in the most positive terms, that 

 a fever has constantly as a part of it, a cold fit appearing al- 

 ways once, or occurring more or less frequently. 



" Here I must observe, that by Bellini and Boerhaave the 

 symptoms of the cold fit are supposed to be produced by a vis- 

 cidity of the blood occasioning its stagnation in the extreme 

 vessels, and this has continued to be the doctrine of all the 

 Boerhaavians till lately ; and M. Quesnay in particular has 

 adopted it. But it would not be difficult to shew that it is with- 

 out foundation, and even Boerhaave himself perceived the in- 

 completeness of it. In the first edition of his Aphorisms, he 

 only mentions the ' viscositas liquidi arteriosa ;' but he has since 

 added, e forte et liquidi nervosi inertia ;' and Van Swieten has 

 entirely deserted the former supposition, and says, that the phe- 

 nomena depend upon a change in the state of the nervous 

 power. Dr. Whytt has expressed himself to the same purpose, 

 that the sense of cold seems not to be owing to viscid fluids 

 stagnating in the extreme vessels, but to a spasmodic constric} 

 tion occasioned by that irritation which the nervous system suf^ 

 fers. Wherefore, from the hint which Boerhaave throws out, from\ 

 the opinion of his commentator, Van Swieten, from Dr. Hoff- 

 mann, and from Dr. Whytt, we lay it down, that the cold fit of 

 fevers is an affection of the nervous system, which I am now to 

 make out more fully." 



XXXV. To discover the cause of the cold stage of fevers, 

 we may observe, that it is always preceded by strong marks of 

 general debility prevailing in the system. The smallness and 

 weakness of the pulse, the paleness and coldness of the extreme 

 parts, with the shrinking of the whole body, sufficiently show that 



2 N2 



