ERUPTIVE FEVERS. 161 



appear very doubtful if any choice be necessary, or can be of 

 any benefit in determining the state of the disease. 



DC XI I. It has been supposed by some, that inoculation 

 has an advantage, by introducing a small portion only of the 

 contagious matter : but this rests upon an uncertain foundation. 

 It is not known what quantity is introduced by the common in- 

 fection, and it may be a small quantity only. Although it 

 were larger than that thrown in by inoculation, it is not ascer- 

 tained that the circumstance of quantity would have any effect. 

 A certain quantity of ferment may be necessary to excite fer- 

 mentation in a given mass ; but that quantity given, the fer- 

 mentation and assimilation are extended to the whole mass ; 

 we do not find that a greater quantity than is just necessary, 

 either increases the activity of the fermentation, or more cer- 

 tainly secures the assimilation of the whole. In the case of 

 the smallpox, a considerable difference in the quantity of con- 

 tagious matter introduced has not discovered any effect in 

 modifying the disease. 



DCXIII. Purging has the effect of diminishing the activity 

 of the sanguiferous system, and of obviating its inflammatory 

 state. It is therefore probable, that the frequent use of cooling 

 purgatives is a practice attending inoculation which may be of 

 considerable advantage ; and, probably, it is also useful by 

 diminishing the determination to the skin. It appears to me, 

 that mercurials and antimonials, as they are commonly man- 

 aged^, are useful only as they make a part of the purging 

 course. 



DCXIV. It is probable, that the state of the smallpox de- 

 pends very much upon the state of the eruptive fever, and par- 

 ticularly upon moderating the inflammatory state of the skin ; 

 and, therefore, it is probable, that the measures taken for mo- 

 derating the eruptive fever and inflammatory state of the skin, 

 afford the greatest improvement which has been made in the 

 practice of inoculation. The tendency of purging, and the use 

 of acids for this purpose is sufficiently obvious ; and, upon the 

 same grounds, we should suppose that blood-letting might be 

 useful ; but probably this has been omitted for the same reason 

 that perhaps might have led to the omission of other remedies 



VOL, II. L 



