21S 



THE CENTURA BOOK OF FACTS. 



The articles are then weighed and suspended 

 in the solution, and are left there until a suf- 

 ficient amount of silver has been deposited 

 upon them. This amount is tested by weight. 

 If the additional weight is not gained within 

 the expected time the article is put in the solu- 

 tion again. When finally taken out, the arti- 

 cles are rubbed with brushes of fine wire and 

 cleaned with fine sand ; they are then polished 

 on revolving brushes with rotten-stone, then 

 with chamois-leather and rouge. The process 

 of electro-gilding is essentially the same, with 

 the exception that gold is substituted for 

 silver. 



Embalming. The ancient Egyptians be- 

 lieved that their souls, after many thousand 

 years, would come to re-inhabit their bodies, in 

 case these latter were preserved entire. Hence 

 arose their practice of embalming the dead. 

 The Egyptian manner of preserving the dead 

 has been the admiration and wonder of modern 

 times. They render the body not only incor- 

 ruptible, but it retains its full proportion of 

 size, symmetry of feature, and personal like- 

 ness. They called the embalmed bodies mum- 

 mies, some of which, buried 3,000 years ago, 

 are perfect to this day. The art of such em- 

 balming is now lost. When Nicodemus came 

 with Joseph of Arimathea to pay the last 

 duties to our Saviour after his crucifixion, he 

 brought a mixture of myrrh and aloes to em- 

 balm his body. Carbolic acid was successfully 

 employed by Professor Seely in America, in 

 1868. The modern method of embalming 

 generally consists of an injection of camphor- 

 ated spirits of wine into the arteries and veins, 

 though many other chemical substances are 

 successfully used. 



Embroidery. Its invention is generally 

 ascribed to the Phrygians ; but the Sidonians 

 excelled in it, and it is mentioned by Homer 

 and other ancient authors, in the year 1491 

 B. C. The latter were particularly skilled in 

 decorative species of needlework. The first 

 embroidery machine is said to have been in- 

 vented by John Duncas, of Glasgow, in 1804. 

 Heilman's embroidery machine was patented 

 by Kochlin. An ancient existing specimen of 

 beautiful embroidery is the Bayeux tapestry, 

 worked by Matilda, the queen of William the 

 First of England. It is nineteen inches wide, 

 214 feet long, and is divided into compart- 

 ments showing the events from the visit of 

 Harold to the Norman court to his death at 

 Hastings. It was reproduced by autotype 

 process, with notes, in 1875. 



Emery is found, upon analysis, to be com- 

 posed of alumina, oxide of iron, and silica, 

 with a little lime. It is a dull, opaque sub- 

 stance, sometimes of a grayish black, some- 



times of a bluish color, and it is prepared for 

 use by crushing the lumps in a stamp mill, 

 and then passing the powder through sieves of 

 different degrees of fineness. For the most 

 delicate uses of opticians the powder is graded 

 by the process known to chemists as elutria- 

 tion. Emery was for a long time brought 

 from the island of Naxos in the Grecian Arch- 

 ipelago. The Greek government granted a 

 monopoly of its trade to an English merchant. 

 In 1847, Dr. J. Lawrence Smith, an American 

 explorer in the employ of the Turkish govern- 

 ment, found deposits of the mineral at various 

 points in Asia Minor, and the monopoly was 

 destroyed and the price lowered. Deposits of 

 emery have since been found in Bohemia, in 

 the Ural Mountains, in Australia, and in North 

 Carolina, Georgia, and Montana. The supply 

 from these deposits is too small, however, to 

 compete with that which is brought from 

 Turkey and Naxos. 



Engraving. The engraving of gems is a 

 branch of art of the highest antiquity. The 

 earliest writers make mention of engraved seals 

 and seal rings, and there still exist many an- 

 tique engravings equal to later productions of 

 similar artists. Engraving from plates and 

 wood is chiefly of modern invention, having 

 its origin about the middle of the fifteenth cen- 

 tury. Engraving on glass was perfected to an 

 art by Boudier of Paris, 1799. The art of 

 engraving, especially in photographic processes, 

 has made great progress in the United States 

 during the past quarter century. Prints from 

 engraved copper plates made their appearance 

 about 1450, and were first produced in Ger- 

 many. Masso is considered to have been the 

 first Italian engraver, about 1440. Etchings 

 on copper by means of aqua fortis is reputed 

 to have been discovered by Francis Mazzuoli, 

 about 1532. Etching was later practiced by 

 Albert Durer, and most especially by Rem- 

 brandt. Its revival began about 1860. Mezzo- 

 tints are said to have been discovered by Col- 

 onel Von Siegen, who engraved the portrait of 

 Princess Amelia of Hesse in mezzotint, in 

 1643; it was improved by Prince Rupert in 

 1648; and by Sir Christopher Wren, about 

 1662. The mode of engraving on soft steel, 

 which after it has been hardened will multiply 

 copper plates and fine impressions, indefinitely, 

 was introduced into England by Messrs. Per- 

 kins & Heath of Philadelphia, in 1819. 



Entomology, the science of insects, is 

 based upon the arrangements of Linnaeus, A. 

 D. 1739. The Entomological Society of Lon- 

 don was instituted in 1833. A national ento- 

 mological exhibition at the Westminster aqua- 

 rium was opened March, 1878. Numerous 

 chairs of entomology have been established iu 



