245 reported on the synthesis of linear but alsobranched polymers prepared by di-, tri-, and tetra-alkyne andazide monomers like the combination of tripropargylamine(B 3)and(dihydroxymethyl)(diazidomethyl)amine(A 2)(com-pare the general outline in Scheme 17).
When discussing mineral formations in caves, we often talk about stalactites and stalagmites. A stalactite is an icicle-shaped formation that hangs from the ceiling of a cave, and is produced by precipitation of minerals from water dripping through the cave ceiling. Most stalactites have pointed tips.
Educational signs in the Luray Caverns in Virginia promote public understanding of the difference between stalactites and stalagmites. Alan Band/Fox Photos/Getty Images We can trace the words stalactite and stalagmite back to the Greek word stalassein, which means to drip. This is fitting because it describes how both are formed in nature. Although they look lifelike and a little creepy, stalactites and stalagmites grow simply because of water running over and through inorganic material.