POPULAR MISCELLANY. 



711 



there are about 172,000 acres of land under 

 vine-cultivation in north and south Bulgaria. 

 The yield of wine per acre varies between 

 250 and 350 gallons, two thirds of which is 

 red wine and the remainder white. The 

 wine in some vineyards is said not to be in- 

 ferior to the best natural wines of other Eu- 

 ropean countries. In 1886 some 140,000 

 gallons of wines were exported from south- 

 ern Bulgaria to the south of France. There 

 they were manipulated and sold as the prod- 

 ucts of the country. The phylloxera made 

 its appearance a few years ago, but stringent 

 msasures were at once taken to stamp it out, 

 and very strict regulations are enforced to 

 prevent its return. 



The Chemistry of an Egg-Shell.— The 

 shell proper of an egg is made up mostly of 

 earthy materials. The proportions vary ac- 

 cording to the food of the bird, but ninety 

 to ninety-seven per cent is carbonate of lime. 

 The remainder is composed of from two to 

 five per cent of animal matter and from one 

 to five per cent of phosphate of lime and 

 magnesia. Now, Mr. P. L. Simmonds asks, 

 where does the hen procure the carbonate of 

 lime with which to form the shell ? If we 

 confine fowls in a room, and feed them with 

 any of the cereal grains, excluding all sand, 

 dust, or earthy matter, they will go on for a 

 time and lay eggs, each one having a perfect 

 shell, made up of the same calcareous ele- 

 ments. Vauquelin shut up a hen for ten 

 days, and fed her exclusively upon oats, of 

 which she consumed '7,4'74 grains in weight. 

 During this time four eggs were laid, the 

 shells of which weighed nearly 409 grains ; 

 of this amount 276 grains were carbonate of 

 lime, IVi grains phosphate of Hme, and 10 

 grains gluten. But there is only a little car- 

 bonate of lime in oats, and whence could 

 this 409 grains of the rocky material have 

 been derived ? The answer to this question 

 opens up some of the most curious and won- 

 derful facts connected with animal chemis- 

 try. The body of a bird, like that of a man, 

 is but a piece of chemical apparatus, made 

 capable of transforming hard and fixed sub- 

 stances into others of a very unlike nature. 

 In oats there is contained phosphate of lime, 

 with an abundance of silica, and the stomach 

 and assimilating organs of the bird are made 

 capable of decomposing the lime-salt and 



forming with the silica a silicate of lime. 

 This new body is itself made to undergo de- 

 composition, and the base is combined with 

 carbonic acid, forming carbonate of lime. 

 The carbonic acid is probably derived from 

 the atmosphere, or more directly perhaps 

 from the blood. These chemical changes 

 among hard inorganic bodies are certainly 

 wonderful when we reflect that they are 

 brought about in the delicate organs of a 

 comparatively feeble bird, under the influ- 

 ence of animal heat and the vital forces. 

 They embrace a series of decomposing and 

 recomposing operations which it is difficult 

 to imitate in the laboratory. 



Fresh- Water Sponges. — The fresh-water 

 sponges, according to Mr. Edward Pott's 

 monograph, resemble in constitution and 

 general appearance many of the sponges of 

 a marine habitat, with the addition that they 

 have gemmules or " seed-like bodies," which 

 marine sponges have not. They are green, 

 but may be distinguished from mosses and 

 Confervce by the diiference between smooth, 

 slender threads and leaves ; by the presence 

 of efferent or discharging apertures; and, 

 with a lens, by their spicules — to which 

 finding the spherical gemmules adds further 

 confirmation. The green color varies accord- 

 ing to the light, and may, in dark places, or 

 dark parts of the sponge, be faded into 

 nearly white, gray, or cream color ; but some 

 species are never gi-een in the sunlight. 

 These organisms have occasionally been dis- 

 covered growing in water unfit for domestic 

 uses ; but as a rule they prefer pure water, 

 and in the author's experience the finest 

 specimens have always been found where 

 they were subjected to the most rapid cur- 

 rents. " The lower side of large, loose stones 

 at the ' riffs ' or shallow places in streams ; 

 the rocks amid the foaming water at the foot 

 of a mill-dam fall; the timbers of a sluice- 

 way, the casing of a turbine water-wheel, or 

 the walls of a 'tail-race' beneath an old 

 mill — in all these places they have been 

 found in great abundance and of a very lusty 

 growth. Of all discouraging situations it is 

 almost hopeless to look for them in shallow 

 water having a mud bottom. ... In any 

 body of water liable to be charged with sedi- 

 mentary material, the principle of natural 

 selection favors those growing on the lower 



