SUMMER MEETING. 



43 



Wool, also, is solid, but has very distinct markings, like bowls piled within 

 each other, only the lines are very irregular and project out around the 

 fiber in a sort of saw tooth manner. These little teeth crawling upon each 

 other when washed is the cause of shrinkage in woollen goods. 



a, SILK 

 *>, WOOL 





Fig. 13. 



Fig. 14. 



Consult Fig. 13, a, for cross and vertical views of cotton; b, the same, for 

 common flax; c, for New Zealand flax. 



Fig. 14, a, shows two smooth, solid threads of silk ; b, two fibers of wool. 

 Dr. Beal: All parts of plants are made up of small cells, some with thin 

 walls like those of elder pith, some with thick walls. To learn something in, 

 regard to why nuts are hard we shall call on one who has examined small 

 fragments under a compound microscope. The next speaker is 



W. W. Diehl : If a piece of hickory 

 nut is boiled in potash and nitric acid 

 it will become softened, and the cells 

 may be separated. When examined 

 under a high magnifying power the 

 cells are seen to be nearly filled — only 

 a small branching cavity remaining. 



In vegetable ivory the small branches 

 of the cell cavity often correspond or 

 meet those of contiguous cells. The 

 walls are very thick and firm. 



The seeds of Japanese persimmons 

 Fig. is. are very hard when dry. The cell walls 



are very thick, the hole within is nearly spherical. Fig. 15 will illustrate the 

 whole thing very well. 



Dr. Beal : The next one on the programme will speak of tough and brittle 

 wood of white ash compared under the microscope. 







Fig. 16. 



Fig. 17 



