274 BULLETIN OF THE BUSSEY INSTITUTION. 
was out of danger. Two months later a couple of fresh mice were 
fed for several days upon mixtures of carbonate of baryta and 
whiting, and it appeared that the whiting acted as an antidote, to 
protect the mice from the poisonous effects of the barium com- 
pound. For several days after their capture these mice received 
4 balls of plain whiting-putty per day, and they ate the whole of 
it. ‘They were then given 4 balls of putty made from oil and a 
mixture of 4 carbonate of baryta and ,%, whiting, but they ate 
only 2 of the balls during the first day. Next day they received 
4 fresh balls of the same baryta mixture and ate them all. They 
were then given 4 balls of putty made from a mixture of + carbo- 
nate of baryta and # whiting, and they ate 3 of these balls. Next 
day they got 4 balls of putty made from a mixture of 4 carbonate of 
baryta and $ of whiting, but to all appearance they ate none of it. 
Next day they were given 4 balls of putty made from pure carbon- 
ate of baryta and oil, and although, so far as could be seen, none 
of the balls were touched, yet the mice both died on the following 
day. A week or two later a mouse that had only just been caught 
escaped from his cage one night, and gained access to one of the 
last-named balls made of pure carbonate of baryta. He carried 
this ball into a corner, and was found there next morning lying 
dead beside the ball, of which he had only eaten a small portion. 
For the sake of certainty this ball was analyzed and found to con- 
sist solely of carbonate of baryta and oil. 
The protective influence above alluded to, of carbonate of lime 
against carbonate of baryta, is a noteworthy fact. It goes to 
show that there may have been something of truth in the ‘‘ fabled ” 
electuary of Mithridates. Further illustrations of the efficacy of 
the lime-carbonate as an antidote will be seen beyond, under the 
head of white-lead, and also in the experiments upon rats. The 
action of it would seem to depend at first sight upon the more easy 
solubility of carbonate of lime * in the acid juices of the stomach. 
It might not unnaturally be supposed that while the lime compound 
goes into solution, the less soluble barium (or lead) compound is 
shielded from the acid solvent and passes off through the intes- 
tines as mere inert matter. But if this explanation be a true one, 
the power of the mice to deal with such masses of carbonate of 
lime as have been described above, becomes all the more extraor- 
* «<The 28 minerals which occur, as pseudomorphs in forms of carbonate 
of lime, are all less soluble than it is.” Bischof, ‘‘ Elements of Chemical Ge- 
ology,” London, 1854, 1. 39. 
