28 VEGETABLE PHYSIOLOGY. [LESSON 9. 



Silk supported a weight of 84 H>s. 



New Zealand Flax 23 4 ' 5 



Common Hemp 16 1-8 



Common Flax 11 3-4 



If the maceration of the fibre be carried on to much extent, a pulp is 

 formed from which paper is manufactured. 



164. In ordinary paper the vegetable structure is entirely de- 

 stroyed, but in the Chinese rice-paper, which is not prepared by 

 maceration, and hi the paper of Japan, made from the mulberry, it 

 is preserved. 



165. The structure of flax, so largely employed in the manufac- 

 ture of linen, is peculiar ; and to guard ourselves against those manu- 

 facturers who employ (frequently) a large percentage of cotton, to be 

 used in manufactures hereafter to be warranted " all linen," it is 

 worth the while to examine it. 



166. If a linen thread be scraped with the thumb-nail to separate 



it into its primitive elements, or ultimate fibres, and 

 placed under the microscope, an appearance will be 

 presented like Fig. 46. 



167. It will now be seen that we have a series of 

 (apparently) solid, cylindrical, many-jointed fibres 

 the joints not very dissimilar to those of a bamboo 

 cane ; really, however, they are tubes, so nearly 

 filled with solid contents that it is by no means easy 

 to satisfy oneself of the fact. 



168. The outer membrane of the tube is struc- 

 tureless, although, occasionally, delicate transverse 

 markings may be seen. 



169. These tubes are of great length, and usually pointed at both 

 ends ; they are also remarkable for their toughness. 



170. Cotton is not woody fibre, but simply the hair of the plant 

 producing it, and will be described under the proper head. 



LESSON IX. 



VASCULAE TISSUE. 



171. The roots of a plant absorb a continued influx of nutrient 

 matter, whjch circulates through it, while the superfluous water is 

 evaporated by the stomata (breathing mouths). 



