472 
Identification  of  Artificial  Silks. 
{Am.  Jour.  Pharm. 
October,  1914. 
not  discovered  until  near  the  end  of  the  operation,  when  it  became 
a  matter  of  great  skill  to  bring  up  the  shade  of  the  indifferent  skeins 
to  the  shade  of  the  main  lot.  This  condition  could  have  been  antici- 
pated had  the  dyer  been  acquainted  with  the  fact  that  the  entire  lot 
of  silk  was  not  of  one  kind. 
From  time  to  time  there  have  been  published  tests  and  reactions 
with  chemicals  to  be  used  in  distinguishing  the  several  kinds  of  arti- 
ficial silks,  but  the  practical  application  of  which,  in  the  dye-house  or 
office,  seems  to  offer  some  obstacles  in  the  hands  of  those  not  actually 
acquainted  with  the  details  of  making  reactions.  It  seems  that  while 
the  method  of  making  the  tests  is  simple  enough,  the  greatest  difficulty 
is  in  having  the  solutions  or  reagents  properly  compounded  and  in 
conducting  the  tests  afterwards. 
Simple  descriptions  alone  do  not  seem  to  meet  the  case  entirely. 
Of  course,  there  is  nothing  to  take  the  place  of  a  practical  demon- 
stration of  a  testing  method  when  carried  out  by  one  who  is  practi- 
cally familiar  with  the  proper  sequence  of  the  operations. 
On  the  other  hand,  many  of  the  methods  for  fibre  testing  that 
have  been  published,  while  apparently  intended  for  dyers  and  prac- 
tical mill  men,  being  those  most  concerned,  are,  as  a  rule,  written 
for  the  chemist  with  some  experience,  as  only  such  could  possibly 
have  the  unusual  reagents  and  apparatus,  or  even  the  apparently  deli- 
cate manipulative  skill,  to  handle  both  satisfactorily. 
Without  question,  the  most  satisfactory  means  to  identify  artificial 
silk  is  to  make  use  of  the  microscope,  but  as  very  few  mills  are 
equipped  with  this  valuable  instrument,  and  fewer  still  are  proficient 
in  making  use  of  it,  we  will  omit  its  discussion  as  applied  to  artificial 
silk  and  confine  ourselves  exclusively  to  the  chemical  or  wet  methods 
that  experience  has  taught  us  as  being  the  most  satisfactory. 
To  identify  artificial  silk  properly  requires  that  the  person  at- 
tempting the  work  should  have  at  hand  a  small  set  of  chemical 
reagent  bottles  of  not  more  than  two-ounce  capacity  and  with  glass 
stoppers.  Such  bottles  are  not  costly  and  may  be  obtained  through  a 
local  druggist ;  the  style  known  as  "  XX  Tinctures  "  are  admirably 
suited  for  the  purpose.  They  are  to  be  filled  with  the  following 
reagents,  which  can  be  procured  from  a  chemical  supply  house  or  pre- 
pared by  a  friendly  pharmacist  or  chemical  friend. 
The  following  constitutes  the  list  and  the  methods  for  their 
preparation : 
