From the "London Medical Record," Jan. 20th, 1875.

J. Etzinger (Zeitschrift fur Biologie, 1874, Band x., abstract in Centralblutt fur die Medicin. Wissenschaften, No.- 45, 1874) tested on the one hand the action of artificial gastric juice on the ligamentum nuchae, tendon, cartilage and bone; and on the other hand fed a dog, whose excretion of nitrogen was diminished to a constant low value by being allowed to hunger for several days, with the proper substances.

The increase in the quantity of nitrogen after the supply of the above substances is taken as the standard for their utilisation in the body.

1. Bones. - Bone powder prepared by rasping the compact substance of ox-bones, dissolved tolerably richly in hydrochloric acid (0.3 per cent.). After ten days' digestion of 10 grammes (150 grains) of the powder, with in all 1,200 cubic centimetres (rather more than 40 ounces) of dilute acid, only 1.83 grammes remained undissolved. The residue was richer in organic substance than the original substance; organic substance, however, being plentiful in the solution. The dog experimented on showed, after taking 150 grammes of bone, an increase in the excretion of urea of about 8 grammes per diem. An absorption of lime from the bones could not be proved; on the contrary, the quantity of this mineral in the urine showed a diminution. The author supposes that the cause of this phenomenon lay in the diminished decomposition of the tissues of the body through the supply of gelatine. The phosphoric acid showed a small increase. Corresponding to this, the feces evacuated during feeding with bones contained 308.5 grammes of ash, i.e., somewhat more than the supplied bones.

2. Cartilage. - Costal cartilage of a calf dissolved in not inconsiderable quantity in a 0'3 per cent, solution of hydrochloric acid (e.g. 24.3 per cent.); but much more on the addition of pepsin (74.9 per cent.). After feeding with cartilage, the feces only contained traces thereof; the excretion of urea showed an increase of about 11 grammes after feeding with 72.2 of dry cartilage at 100° Cent.

3. Tendons were affected little by the action of a 0.3 per cent, solution of hydrochloric acid. After eight days' digestion the amount dissolved in the pepsine mixture was 1205 per cent.; on the contrary, after three days they were broken up and dissolved, and 94 per cent, had gone into solution. The solution did not form a jelly after neutralisation and evaporation. The ligamentum nuchas of an ox conducted itself similarly; on digestion for ten days it disappeared completely, only an unimportant residue remaining. The dog, after hungering for several days, received in one day 367.1 grammes of tendon, on the next 360.3 grammes, corresponding to 245.8 grammes of the dried substance. In the feces only a very minute quantity of tendon could be found. The excretion of nitrogen in the urine rose to 21.2 grammes (the tendon contained 46.4 grammes).

"All gelatine-yielding tissues are therefore capable of digestion and utilisation; most extensively tendon, then cartilage, and lastly bone, of which less organic substance is absorbed, probably on account of its rapid passage through the intestinal canal. The author confirms the results of Frerichs and Kuhne, that gelatine, by digestion with pepsin and hydrochloric acid, loses its property of gelatinising."