THE JOURNAL OF PHARMACOLOGY. 225 



thread were obtained. One of the warp threads was twisted, consisting 

 of two yarns, one of which, K„, was black, and the other, Ki., white. Two 

 warp threads, K^, A's, were dark blue and the fourth, A'4, was mixed 

 gray. The wool was blue. 



The examination gave the following results : 



Ka 85 shoddy threads (most black, but also some red-yellow and a few 



green sheep's wool threads and 13 cotton threads). 

 K^ 31 pure white sheep's wool threads. 

 K^ and K^ pure blue sheep's wool threads, respectively 46 and 53. 



' K^ 60 shoddy threads, 32 of which were chiefly gray or black sheep's 

 wool threads and 28 gray cotton threads. 

 E 60 blue sheep's wool threads. 



Therefore in one piece of this sample which consisted of four woof 

 andjfour warp threads were found 85 + 31 + 46 + 53 + 60^275 single 

 warp fibers, and 4X60^240 woof fibers; together 515 single fibers, of 

 which 13 + 28 = 41 were cotton and were found entirely among the 

 shoddy, which embraced 85 + 60= 145 fibers. This square sample con- 

 tains woof and warp threads of equal length consisting of 41 cotton threads, 

 104 shoddy sheep's wool threads, and 370 pure sheep's wool threads, from 

 which their respective per cents, may easily be calculated. Naturally the 

 percentage of the number of fibers only is secured in this manner. If it is 

 desirable to ascertain their relative weights, microscopical determinations 

 must be made. If by means of numerous measurements the average 

 thickness of the cotton and woolen fibers in the sample has been ascer- 

 tained, then taking into consideration the circumstances, that a sheep's 

 wool fiber with same diameter as the greatest one of a cotton fiber will 

 have a surface on cross section that is twice as great as that of the latter — 

 for cotton is always greatly flattened — it will be easy to calculate their pro- 

 portion by means of which the per cent, of weights may be obtained. It 

 has of course been assumed that the specific weight of sheep's wool is the 

 same as that of cotton. Furthermore, no allowance is made for the dye 

 and mordant of the fibers. 



lyCt .y be the diameter of the sheep's wool and b that of cotton, then the 

 ratio of the cross section will be for the present, 



2 b^ 



Multiplying the size obtained above for the number of threads in the 

 sheep's wool by 2s'^ jb"^ the relative weight of sheep's wool and cotton is 

 obtained for sheep's wool is, owing to the fact that its cross section is 

 twice as great as cotton, heavier than the latter. 



For example, if a sample has the same number of equally thick threads 

 of cotton and sheep's wool, then their relative per cents, for the number 



