Interesting, HMX, have you ever done any glass blowing yourself? I have often considered giving it a try, for making custom bits of glassware and the like.
Apparently, a Kjeldahl flask is used for determintation of nitrogen content in a proteine containing sample, I am buying it off ebay, its only costing me £0.99, which is actually cheaper than the shipping price, not bad for pyrex, it just happens to be pretty well suited for the distillation of the 1,4-BDO I am experimenting with, as the neck is narrow enough to plug with clay and glass tubing, as the 1,4-BDO would probably attack rubber or plastic stoppers and be unsuitable for my experiments.
Ebay really is the best, for the amateur chemist, theres almost nothing you can't buy there, the only things I have EVER failed to find, are concentrated liquid acids, pyridine, and LiAlH4, everything else, they got it