Not sure what's up with the crazy fonts. Frustrating.
I believe it is well ascertained that the bladder of the frog acts as a reservoir for the moisture necessary to its existence: such seems to the the case with the tortoise. FOr some time after a visit to the springs, their urinary bladders are distended with fluid, which is said gradually to decrease in volume, and to become less pure. The inhabitants, when walking in the lower district, and overcome with thirst, often take advantage of this circumstance, and drink the contents of the bladder if full; in one I saw killed, the fluid was quite limpid, and had only a very slightly bitter taste. The inhabitants, however, always first drink the water in the pericardium, which is described as being best." Charles Darwin, Voyage of the Beagle
I don't often drink from the body parts of a dead tortoise, but when I do, I drink from the sac that surrounds the heart.