flexed DifTertitaon of the Origin and Cure of Rheumes.Ks to their OrU 
gin^ the Learned Author, having declared, with the generality of 
Phyiitians, iwcc Rh^Umei are bred from the Serous part of the Bioud, 
t2Ver*d from it by an impeded Tranfpiration, he undertaketh to e- 
vince the erroneoufnefs of the Vulgar opinion, deriving all forts of 
Defiuxions. from the Brain, by (hewing , that, whereas the Authors 
and Teachers of that Tenet do acknowledge, that the Water colle- 
dcd in the Ventricles of the Brain deftilleth only through the Ot 
Cribrl forme- into the Nofe, and through the GUndnU pimtaria into 
the Palat V the Strudureof thofe partsis fuch, that that can be done 
neither of thcfe waycs ^ which aflertion of his is accompanied with 
divers confiderable Obfervations and Experiments ^ asalfo with an 
Anfwcr to thofej that apprehend great danger to the Brain from the 
excrementitious matter gathered therein, if it Ihould not be purged 
out from thence by the Eyes, Noftrils, Ears and the Palat. Which 
being difpatched, he proceeds to fuggeftthe wayes of flopping and 
curing Defiuxions, by obferving,that,fince the Matter for Rheumcs is 
furnilhed by the i'^fr^w; of the Bloud, whatever is able to withdraw 
thztpdu/um^ or to jtrecipitate the ferofity through the Kidneys, or 
to convey it away by fiege, or to difpcll it through the pores of the 
Body, is fufficient to perform the cure. 
IV. Francifci dc le Boe Sylvii M, D. & Prof, Oratio ie AT- 
F ECTV S EF I DE M 1 1 , A. 1669. Leidam defofulainis^ 
CAVS IS NATVRALIBVS. Lugduni Bauvorum , 
J 670, in 12.'', 
THis Learned Difcourfe , together with the Firfl: part of the 
Praxis Mediae Usa Nova, was lately in feveral Copies prefent- 
ed from the Worthy Author, both to his Majefly^ and to the Royd 
Society, and particularly to the Noble Prefident and divers Eminent 
Members of the fame for their Examination. And as we gave very 
lately a frefli Accompt (in Nfitnh, 71. ) of the faid Firfi part now 
perfed , after we had taken fome notice of it formerly, (in Numh, 
40.) when it was yet incompleatly printed ^ fo we cannot omit to 
give here a Breviat of this ingenious Oration. 
In it the Author dedareth and endeavors to prove, that the late 
wafting Difeafe in the City of Leiden is to be imputed to thefc 
concurrent fecond Caufes, viz.. The ExccffiVe Heat, long conti- 
nued Calms, want of Rain, and the Vapors of Standing and Mud- 
dy waters abounding in that place, together with certain Salin and 
noxious Exhalations of the Earth, by the force of the Sun propelled 
•nto the Air, and there mingled with the former. From which, be- 
^ng v/ell confider'd , he efteems, that all the various and even the 
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