614 PRACTICE OF PHYSIC. 



practice, where we generally employ porcelain cups. I have 

 frequently observed, that in the plates in this house, the size of 

 the blood appears very considerable with respect to its thick- 

 ness, and that it is expanded even over the whole of the sur- 

 face ; while in the porcelain cups it is generally contracted into 

 an insula, forming a sort of hollow cup upon the surface of the 

 crassamentum ; and upon turning the whole mass from the tin 

 plate, very little separate serum appears, whereas in the porce- 

 lain cups the serum is generally in considerable proportion. 



" Many practitioners are too rash in concluding the absence 

 of a phlogistic diathesis, when the blood shews no inflammatory 

 crust, and on this account do not proceed in blood-letting : but 

 this negative is of no weight at all, as it may depend on some 

 of the circumstances in drawing the blood already mentioned ; 

 and it is therefore dangerous to conclude against the existence 

 of a phlogistic diathesis from the absence of the crust. Where 

 it is present, it determines us in favour of the repetition ; but 

 even this is not always certain ; for, even in fevers of the nerv- 

 ous kind, the inflammatory crust may be distinctly marked, and 

 we are in danger of being led astray by it." 



9. The effects of the blood-letting that may have been al- 

 ready practised. " If the pulse is manifestly contracted and 

 small in persons whose habit and time of life should allow of 

 one more full ; and if the venesection seems to strengthen it, 

 as it by relaxing the system allows the pulse to become fuller 

 and to appear stronger, we consider this as a proof of the pro- 

 priety of the bleeding which we have practised, and repeat it 

 with confidence. 



" There is a question occurring in practice, which is indeed 

 the most difficult, viz. when, in the advanced state of fevers, 

 we have symptoms of topical determination, and at the same 

 time there is a very general debility prevailing in the system, 

 as in the case of typhus ; when there are sometimes topical 

 determinations to internal parts, particularly to the brain, which 

 end in death ; and when, with all the symptoms of debility, we 

 find that actual inflammation and suppuration has taken 

 place in the brain ; when this appears in the advanced 

 state of typhus, and when no so sort of irritation, not even 

 the smallest quantity of wine, can be applied without ag- 



