208 



tain external characteristics by means of wliicli it is possible to deter- 

 mine beforehand the sex to be iiatched from tbem. Thus, the " male" 

 egg has, at its pointed end, small folds and wrinkles, while the " female" 

 egg is entirely smooth, and well rounded off at both ends. 



Blackening stone. — A method of rendering stone comi)letely black, 

 to serve as a foil to some other color, or to protect it against the weather, 

 consists in heatiug it in an oven to about 140°, and then removing it 

 and dipping the side to be colored into a vessel filled with melted tar. 

 After removal, the suri)lus is allowed to drain oft", and laid not far from 

 the stove to dry. When it is half dried, it is placed in the air and 

 allowed to 'become completely dry, after which a wisp of straw is used 

 to rub off the blackened side, which gives to the stone a brilliant luster, 

 and prepares it for further use. 



Origin of maize, — The claim that the maize, or Indian-corn plant, 

 is indigenous to the soil of the New World, has lately been contested, 

 and recent investigations of certain Chinese records are cited to prove 

 that it was cultivated in China prior to the discovery of America. Chi- 

 nese authors maintain that it came originally from countries west of 

 China, and that it was introduced into that country long before the first 

 arrival of the Portuguese, in 1517. 



EussTAN METHOD OF PRESERVING FRUIT. — A method of preserv- 

 ing fruit, quite frequently adopted in Russia, consists in slacking fresh 

 lime by sprinkling it with water and adding a little creosote. The fruit 

 is to be packed in wooden boxes, with a layer of the prepared chalk pow- 

 der of an inch in de])th at the bottom. This layer is to be first covered 

 with a sheet of pajjcr, and upon it the fruit is to be laid so as not to 

 touch each other. On the first layer of fruit another sheet of i)aper is 

 placed, with the lime powder sprinkled over it, and a sheet of paj^er over 

 this ; upon this another layer of fruit is spread, as before, and the pro- 

 cess continued until the box is full. The corners may then be tilled with 

 charcoal. If a tight-fitting cover is put on the box, the fruit, it is said, 

 will maintain its freshness for at least a year. 



Manure from Indian corn. — It is said that a new manure is pre- 

 pared in France from Indian corn, a substance now largely used in 

 French distilleries. The grain, previously coarsely broken, is first sub- 

 jected to the action of dilute sulphuric acid, to convert its starch into 

 sugar. After fermentation the refuse is placed in large tanks, and when 

 all the solid matters have subsided the clear liquid is drawn off, and the 

 residue yields an excellent manure, containing about 9 per cent, of 

 water, G8 per cent, of organic matters, including nearly 5 per cent, of 

 nitrogen, and about 19 i)er cent, of mineral matter. 



Sulphuric acid for destroying weeds in lawns. — A writer in 

 an English journal suggests the use of ordinary sulphuric acid or oil 

 of vitriol, as an excellent agent for the destruction of weeds on lawns. 

 The difficulty of eradicating such unsightly elements of the lawn is well 

 understood, since to do so satisfactorily requires the removal of a large 

 amount of dirt, producing a corresponding injury to the general ai)pear- 

 ance. By taking the acid in question, and allowing a few drops to fall 

 into the crown of any obnoxious weeds, it will turn them brown in an 

 instant, and ultimately cause the death of the plant. Great care must 

 of course be taken to prevent any of the acid from falling upon the 

 skin, or any article of clothing; but with ordinary care a large amount 

 of surface can be treated in a short time with most excellent results. 



