Vegetable Tissue. 227 



purposes it is given with liquorice, in the form of a tea ; though 

 Allston remarks it should always be exhibited in the state of 

 powder. It is best used while fresh ; and the tops, before the 

 flowers are formed, possess the most virtue. Cullen gives "it 

 feebly astringent powers, and passes it by with little other re- 

 marks. 



Vegetable Tissue, 



Lindley observes that if plants are considered with reference 

 to their internal organization, they appear at first sight to consist 

 of a vast multitude of exceedingly minute cavities separated by 

 a membranous substance. More exactly examined, it is found 

 that these cavities have a variety of different figures, and that 

 each is closed up from those that surround it ; and if the inquiry 

 is carried still farther, it will be discovered that the partitions be- 

 tween the cavities are all double, and that by maceration in 

 water and other processes, the cavities, with their enclosing 

 membranes, may be separated from each other into distinct bodies. 

 These constitute what is called Vegetable Tissue, or Elemen- 

 tary Organs. Their chemical basis has been found to be oxy- 

 gen, hydrogen, and carbon, with occasionally a little nitrogen, 

 combined in various proportions. Their organic basis is mem- 

 brane and fibre. Membrane varies in degree of transparency, 

 being occasionally so exceedingly thin as to be scarcely discov- 

 erable, except by the little particles that stick to it, or by its 

 refraction of light ; and sometimes having a perceptible green 

 color, and a thickness which is considerable, if compared with 

 the diameter of the cavity it encloses. Fibre may be compared 

 to hair of inconceivable fineness, in diameter not often exceed- 

 ing the T ^ of an inch ; it has often a greenish color, but it is 

 more frequently without any, and transparent. The forms under 

 which the elementary organs are seen, are Cellular Tissue, 

 Woody Fibre, and Vascular Tissue. 



Cellular tissue generally consists of little bladders or vesicles 

 of various figures, adhering together in masses. Occasionally it 

 •is composed of fibre only, unconnected with membrane. It is 

 transparent, and in all cases colorless ; when it appears other- 



