OR, A TREATISE ON PILE. 41 



diameter, y^ 1 ^ of an inch; button, white, transparent, quill-shaped; shra'h, white, 

 opaque; apex, rounded; cortex, is divided by dark lines; central portion, yellow. 



See fig. 45, where No. 1 represents the cortex and the interior, where ihe cortex 

 has been removed; No. 2, the fissure in the cortex; No. 3, grains of cortex removed from 

 the stalk; No. 4, a disk; No. 5, tufts of the wool. 



OF THE INTERMEDIATE FIBROUS PART OF PILE. Between the cortex and the central 

 portion of a perfect hair, and in the interior of an imperfect one, is found a fibrous 

 substance, constituting the strength of the pile, 'which next demands our attention. 

 Sometimes, when the cortex is sufficiently translucent, these fibres may be seen through 

 it, in longitudinal strife, extending nearly the whole length of the shaft; they are then 

 most apparent near the button, and vanish asyoti approach the apex; which may, possibly, 

 be owing to their greater attenuation at the latter place. In an imperfect hair they extend 

 to the centre of the shaft. 



Fig. 46 a represents a hair of the Hon. Henry Clay, artificially deprived of the cortex, 

 except a small portion, left purposely, for comparison. For the most part, the fibres are 

 seen in fasciculus; and the few narrow strips of the cortex are identified by their trans- 

 verse striae. Their diameter is ^-gV<r to ^/JT f an inch- 

 Fig. 46 b represents a hair of a male white, of 25, the posterior termination of which 

 has been split, and the fibrils are seen. 



Fig 46 c is a hair of a person affected with scrofula, (which was disrupted in the act of 

 drawing,) showing the fibres and fibrils. 



Fig. 46 d represents the fibres of a hair of the head of a Choctaw Indian, the cortex 

 having been entirely artificially removed; a and b are bundles of fibres; c and d are 

 fibrils. 



Henle says that the fibrils of pile arejlat; but we have never been able to determine the 

 shape. Henle also savs that they are inelastic and brittle. This does not accord with 

 our experience. We submitted an inch of the hair of the head of our esteemed friend, 

 Wm. F. Van Amringe, Esq., to the operation of the trichometer. It showed no disposition 

 to stretch with a weight less than 290 grains, when it lengthened J ff of an inch. With 

 670 grains, it stretched only 2 T , and with 820 grains, only -fa of an inch; but, upon 

 50 grains being added, it stretched -fa, and with 50 more, only, it stretched i-fj- of an inch. 



Upon examining .the facture, under the microscope, after the manipulation had been 

 completed, the cause of this extraordinary progression was revealed. The cortex had 

 parted in two places, corresponding to the sudden movements above noticed. After the 

 last fracture of it, the fibres (being left to bear the burthen of the weights used in the 

 succeeding experiments) did not yield suddenly and break, as they ought to have done, 

 had the fibrils been inelastic and brittle, as Henle teaches; but the one inch of hair 

 gradually elongated to |# of an inch, and finally parted with 1,570 grains. 



OF A CRUSHED HAIR. Fig. 47 represents a hair of His Excellency General Andrew 

 Jackson, artificially crushed so as to expose the fibrous construction ; a, the crushed portion, 

 has a diameter of ^V part of an inch, while Z, the hair in its normal condition, is only 



