[ 597 ] 
difcover itfelf by this method of trial ; for upon 
adding one fourth of a grain of the fait, this mix- 
ture indantly became of a bright purple : and I 
have found, by other experiments, that the fm ailed: 
quantity of fait of deel thews itfelf as readily in the 
chyle by galls, as in any other liquor of the fame 
confidence. 
This experiment (which was as fair as could have 
been delired), together with another obfervation I 
have made, viz. that neither the blood nor urine of 
patients, during the ufe of fait of deel, in the lead 
change colour with galls, renders it more than pro- 
bable, that this fait does not enter the blood. 
As the fait was found to have undergone no change 
in the fmall guts, it appears, that it is not prevented 
from entering the ladteals by its being decompofed or 
precipitated, as has been imagined ; but, on the con- 
trary, that what renders it incapable of being received 
by thefe vedels, is its aftringency : for the la&eals feem 
to be endowed with that admirable faculty of admit- 
ting fuch particles of pure chyle as they happen to 
be in contact with, and of accommodating their 
diameters to them, at the fame time that by their 
natural irritability, and power of condridion they ob- 
dinately exclude luch as are adringent; which, were 
they to enter the ladeals, would either produce dan- 
gerous obdrutdions in thefe vedels, or, if they got 
into the blood, would occation polypous concretions 
in the larger vedels, or coagulations incapable of be- 
ing tranfmitted thro’ the minute vedels of the lungs; 
the effects of which would be either fudden death, 
or at lead inflammations and fuppurations from ob- 
ftrudions in the pulmonary vedfels ; inconveniences, 
which 
