92 GLUE. ORDER OF EDENTATA. 



Hare. One half of this quantity of Beaver hair covers as much, 

 and produces a much handsomer effect ; but from its great price, 

 it is seldom used except in mixture with other hair. Finally, to 

 complete the manufacture of a hat, the felt is softened by steam, 

 and formed on wooden blocks ; then it is dyed, and its interior 

 surface glued to impart to it greater n'rmness. This branch of 

 manufacture is carried on almost every where in France ; but is 

 most extensive in Paris and Lyons. There are about 1,100 hat 

 manufactories in France, in which 17,000 workmen find employ- . 

 ment, and the annual product of their labor is estimated at nine- 

 teen millions of francs, (or more than three and a half millions 

 of dollars;) but the business has decreased in importance of late, 

 owing to the general use of silk hats. 



79. After the hair and fur have been removed from them, these 

 skins are converted into glue. The skin is insoluble in water, 

 under ordinary circumstances ; but if it be boiled for a long time 

 in that liquid, it softens, dissolves, and is transformed into a par- 

 ' ticular product called gelatine, which on cooling forms a jelly 

 more or less solid. The same is true of the tendons and various 

 other tissues of the animal economy, and the gelatine thus ob- 

 tained constitutes common glue.] 



LESSON VIII. 

 OKDER OF EDENTATA. Zoological Characters. Division into 



three families. 



FAMILY OF TARDIGRADA. Organization. Habits. ./?/, or Sloth. 

 FAMILY OF ORDINARY EDENTATA (Armadillos, >ft tit-eaters, Manis.) 

 FAMILY OF MONOTREMATA. Peculiarities of their Organization. 

 . Ornithorynchus. Echidna. 

 ORDER OF PACHYDERM AT A. Zoological Characters. Peculiarities 



of their Organization. Division into three families. 

 FAMILY OF P'ROBOSCIDIANA. Genus Elephant. Organization. 



Habits. Use. Ivory, (Elephants of Asia, Africa, and Siberia) 



ORDER OP EDENTATA. 



1. Under this head is placed a considerable number of ani* 

 mals remarkable for a certain slowness and want of agility owing 

 to the position of their extremities. In general their toes are 



79. Are the skins of any use after the fur and hair have been removed from 

 them? What is glue? 



1 What is the distinctive character of animals belonging to the order 

 Edentata ? How is this order divided ? How is the Tardigrada distin- 

 guished from the ordinary Edentata? (See table.-) How are the Monotre- 

 mata distinguished from the other two families of this order ? 



