MISCELLANY. 



251 



but little for ornament. The ordinary ser- 

 vice of a set of teeth is about five years, 

 but they frequently last much longer. All 

 full upper sets are retained by atmospheric 

 pressure. This principle is coeval with the 

 art. In Japan, dentistry exists only as a 

 mechanical trade, and the status of those 

 who practice it is not very high. It is, in 

 fact, graded with the carpenters their 

 word hadyikfsan meaning tooth-carpenter. 



Vegetable Ivory. The kernel of the 

 corrozzo-nut so closely resembles ivory as 

 to merit the title of vegetable ivory. The 

 plant {Phytclephas macrocarpa) which pro- 

 duces this nut belongs to the palm-tribe. 

 It grows in South America, and possesses 

 extraordinary beauty. The stem is short, 

 and lies along the ground, but from its 

 crown issues a sheaf of light-green, pinnated 

 leaves, like ostrich-plumes, which often at- 

 tain a height of 30 or 40 feet. The fruit 

 of the plant is as large as a man's head, 

 and contains a number of nuts of rough, 

 triangular shape, each being almost as large 

 as a hen's-egg. When fully ripe, the kernel 

 of the nut is very hard and white, and hence 

 the name phytelephas {vegetable ivory). This 

 is now largely used as a substitute for ele- 

 phant ivory, in the manufacture of buttons 

 and various ornaments, and might easily 

 pass for the animal product. Indeed, the 

 best judges are often deceived by the close 

 resemblance between the two. Advantage 

 is taken of this circumstance in Germany 

 by dealers in bone-dust to adulterate their 

 wares with the waste of the factories where 

 the vegetable ivory is manufactured. The 

 best mode of detecting the adulteration is 

 to burn the suspected article. If it contains 

 any considerable amount of the vegetable 

 substance, the application of heat will cause 

 it to give out an odor much like that of 

 roasting coffee ; but, if it is pure bone-dust, 

 or nearly so, it will emit a nauseous and 

 very disagreeable stench. 



Coloring Matter in Blood. A writer in 

 Virchow's Archiv finds in blood two dis- 

 tinct coloring-matters. One of these is 

 readily soluble in water and alcohol, but 

 not so readily in ether. When dry it has a 

 dark, greenish-brown color, and is carbon- 

 ized on the application of heat, without 



ebullition. The ash is strongly colored 

 with iron, and contains phosphoric and 

 silicic acids, and a trace of alkali. It does 

 not yield hemin-crystals under any treat- 

 ment. With guaiacum-tincture and turpen- 

 tine-oil it gives the well-known blue color, 

 and under the spectroscope is found to pos- 

 sess the characters attributed to alkaline 

 oxyhematin by Preyer. It appears to be 

 identical with Von Wittich's hematin. The 

 other coloring-matter consists of dark, blue- 

 black microscopic crystals, insoluble in 

 water, alcohol, ether, chloroform, and acids, 

 but soluble in weak alkaline solutions, to 

 which they give a brownish tint. If it be 

 then precipitated by acetic acid, and dried, 

 it will, on being treated with sal-ammoniac 

 and glacial acetic acid, yield beautiful he- 

 min-crystals. When reduced to an ash, it 

 consists of pure oxide of iron. It seems to 

 be identical with Virchow's hematoidin. 



Elimination of Carbonic Acid by the 

 Skin. The amount of carbonic acid given 

 out of the system through the skin in man 

 has been variously estimated by physiolo- 

 gists ; but, as their methods of determina- 

 tion were all more or less defective, it ia 

 not surprising that their results should dif- 

 fer very considerably from one another. 

 Thus Reinhard's estimate makes the av- 

 erage daily elimination of carbonic acid 

 through the skin about 35 grains, while 

 Gerlach makes it 120 grains ; other authori- 

 ties ranging* all along between these two 

 extremes. A special apparatus has been 

 devised by Dr. Aubert, of Rostock, for more 

 accurately ascertaining the amount of this 

 excretion. He seats a person within a 

 box, which fits lightly around the neck, 

 and through which a gentle current of air 

 is passed. Dr. Aubert, in this way, finds 

 that in the course of 24 hours a maximum 

 of 97 and a minimum of 35| grains of car- 

 bonic acid are eliminated by the skin of 

 the whole body, exclusive of the head. Va- 

 riations of temperature will of course affect 

 the amount of carbonic acid thus excreted. 

 In the experiment, the external temperature 

 wa3 about 86 Fahr. 



Remarkable Diamonds. A diamond waa 

 recently discovered, at the Cape of Good 

 Hope, which weighs 288 carats. This the 



