Additional Experiments.

Experiment 11. Take a portion of the decalcified bone obtained from
Experiment 4, and wash it thoroughly in water: in this it is insoluble.
Place it in a solution of carbonate of soda and wash it again. Boil it
in water, and from it gelatine will be obtained.

Experiment 12. Dissolve in hydrochloric acid a small piece of the
powdered bone-ash obtained from Experiment 3. Bubbles of carbon dioxid
are given off, indicating the presence of a carbonate. Dilute the
solution; add an excess of ammonia, and we find a white precipitate of
the phosphate of lime and of magnesia.

Experiment 13. Filter the solution in the preceding experiment, and
to the filtrate add oxalate of ammonia. The result is a white
precipitate of the oxalate of lime, showing there is lime present, but
not as a phosphate.

Experiment 14. To the solution of mineral matters obtained from
Experiment 3, add acetate of soda until free acetic acid is present,
recognized by the smell (like dilute vinegar); then add oxalate of
ammonia. The result will be a copious white precipitate of lime salts.

Experiment 15. _To show how the cancellous structure of bone is
able to support a great deal of weight_. Have the market-man saw out a
cubic inch from the cancellous tissue of a fresh beef bone and place it
on a table with its principal layers upright. Balance a heavy book upon
it, and then gradually place upon it various articles and note how many