112 ANALYTIC SECT. XII, 
or coloured bodies in the lacteals, but always in 
the veins. It does not seem very clear that this 
subject deserves any very great consideration; for 
these contradictory facts only infer, that some- 
times the lacteals absorb coloured fluids, and some- 
times they do not. The nature of the substances, 
and the difference of the animals employed, in 
the experiments of these physiologists, will pro- 
bably go some length in explaining their discor- 
dant results. 
ccLxviu. If the chyle be coloured with a 
mild vegetable substance in the intestines, it is 
not very easy to conceive a power in the lacteals, 
of separating the colouring matter from the chyle; 
but it is easy enough to understand why the lac- 
teals of a graminivorous animal should reject 
alcohol and essential oils. Although I am decid- 
edly in favour of the absorption of various sub- 
stances by the lacteals, yet I must confess that 
in one attempt made by Dr. Sillar and myself to 
prove this opinion, we were disappointed. 
ccLx1x. Sir Everard Home found rhubarb 
in the urine of an animal whose thoracic duct had 
been tied previously to swallowing that medicine, 
which must consequently have found its peony 
to the bladder by the veins. 
ccLxx. When the thoracic duct of a dog is tied, 
its coats contract on its contents with violence 
sufficient to rupture themselves ; but even Haller 
himself conceded contractibility to this tube. 
