On the Salivary Defluxions in Horses. 351 
ver had been extensively cultivated ; and not occurring 
at all in many places, where horses are pastured almost 
altogether on clover; sufficiently proved that opinion 
to be erroneous. It was also imputed to the effects of 
gypsum on plaister so frequently used to promote the 
growth of clover, but the occurrence of it on many farms 
where no plaister had been used, as well as its not 
having occurred on many where it had been used very 
copiously, proved this opinion equally incorrect with 
the former. ; 
My friend Dr. William Baldwin of Wilmington in- 
formed me, that a member of the Linnean society of 
Philadelphia had supposed, that the ptyalism was caused 
by aspecies of the euphorbia. He also politely favoured 
me with a specimen of the species to which it was im- 
puted, and gave me some information on the Euphorbia 
Americana in general, which extensive knowledge of 
botany enabled him to do. For the purpose of as- 
certaining the fact, I procured a small quantity of 
the Euphorbia maculata, and gave it to my horse en- 
veloped in a small quantity. of clover carefully gathered 
stem by stem, and perfectly free from all other vegeta- 
bles or any extraneous matter whatever. A preterna- 
tural discharge of saliva took place in less than half an ~ 
hour. This experiment was frequently repeated, and 
invariably with the same result. To ‘prove that clover 
did not contribute towards it, in some cases other grass 
was used as an envelope with the same effect. And when 
the horse was perfectly free from ptyalism, a conside- 
rable quantity of clover carefully gathered without the 
euphorbia was given to him, and no such effect was 
produced. 
