Am.  Jour.  Pharm. 
Feb.,  1886. 
Whiting  and  Its  Manufacture. 
81 
"  Cliffstone,"  from  which  only  one  grade  is  made,  and  that  is  shown 
as  B  No.  1,  "Cliffstone  Paris  White."  Each  of  these  grades,  here 
shown,  are  products  of  the  kiln-dried  method,  and  differ  from  each 
other  in  fineness  of  powder  and  certain  physical  qualities  which  adapt 
them  for  various  special  uses. 
It  may  be  of  interest,  at  this  time,  to  present  a  table  of  whiting 
analyses  (kiln-dried  product).  The  specific  gravity  of  each,  in  the 
powdered  state,  was  taken  in  a  specific  gravity  bottle  and  may  vary  in 
some  instances  from  the  moisture  absorptive  power  of  certain  of  the 
powders,  hence  they  must  be  considered  as  relatively  approximate  and 
not  as  a  standard.  Concerning  the  estimation,  of  the  constituents, 
alumina,  ferric  oxide  and  magnesia,  they  were  present  in  such  small 
quantities,  in  chalk  and  cliffstone,  that  their  determinations  were 
ignored.  The  moisture  was  calculated  by  heating  1  gm.  of  the  powder, 
of  each  grade,  in  an  air-chamber,  at  a  temperature  of  not  more  than 
212°  F.  (100°  C.)  for  one  hour  or  more,  until  it  ceased  to  lose  weight. 
The  quantity  of  silica  present,  which,  in  the  whitings  at  least,  was  the 
amorphous  variety,  was  found  by  dissolving  the  dried  powder  in  acetic 
acid,  filtering  through  tared  filters,  washing  thoroughly  with  distilled 
water,  and  weighing  residue  on  the  filter,  after  thorough  drying,  as 
silica.  The  calcium  carbonate  was  estimated  by  the  difference  between 
the  sum  of  the  moisture  and  silica,  and  the  total  weight  of  the  dried 
powders  used  (i.  e.,  1  gm.).  Since  the  crude  products  vary  greatly, 
and  the  manufactured  goods  differ  to  some  extent  from  each  other, 
according  to  the  maker,  the  results  of  the  table  appended  cannot  be 
taken  as  a  standard,  but  as  only  an  approximate  indication  of  the 
general  constitution  of  whiting. 
TABLE  OF  WHITING  ANALYSES. 
Grades. 
A. 
No. 
B. 
No. 
a 
No. 
1,  Crude  Chalk  
2,  Commercial. ,  
3,  Gilded  
4,  Am.  Paris  White 
1,  Cliffstone  
2,  C.  Paris  White... 
1,  Creta  Praparata  (U.S.P.).. 
2,  Calcii  Carb.  Pr^ec.  (U.S.P.) 
Sp.  gr. 
Moisture 
(pr.  ct.) 
Ca  C03 
(pr.  ct.) 
Silica 
(pr.  ct.) 
263 
5,  10,  20 
91,    86,  76 
4- 
2-5 
96-5 
3-5 
2-38 
97- 
3- 
2-32 
98- 
2- 
2-63 
5,  10,  20 
90-5,  85-5,  75-5 
4'5 
2-5 
96- 
4- 
2-5 
96- 
4- 
225 
100- 
