Am  Tour.  Pharm.  ) 
May,  1880.  J 
Gum- Hogg. 
25J 
mucilage  formed  by  this  gum  possesses  no  adhesive  qualities,  and  thiis 
is  well  fitted  for  its  peculiar  use,  although  not  superior  to  simikr  mucil- 
ages obtained  from  flaxseed,  elm  bark,  quince  seed,  etc. 
Of  late  years,  it  has  gone  considerably  out  of  use  on  account  of  the 
irregularity  and  scarcity  of  the  supply,  being  substituted  by  some  of  the 
other  mucilages  before  mentioned. 
From  all  these  facts,  the  writer  concludes,  that  gum-hogg  is  not  the 
product  of  any  particular  tree  or  plant,  but  is  a  trade-name  applied  t©> 
various  cheap  and  inferior  gums,  all  probably  identical  with  Bassora  gum,, 
and  containing  and  consisting  almost  entirely  of  bassorin. 
In  this  connection,  before  concluding,  it  might  be  interesting  togsve 
a  short  account  of  its  use  in  the  manufacture  of  books.  The  process 
in  which  it  takes  a  part  is,  that  of  "marbling,"  as  it  is  termed,  which 
consists  of  staining  paper  and  the  edges  of  books  in  a  peculiar  aod 
variegated  manner.  The  gum  is  first  allowed  to  soak  in  cold  water 
until  swollen,  and  then  boiled  with  a  weak  solution  of  pearlasb  untal 
a  thick  consistent  mucilage  is  obtained,  which  is  strained.  This  forms 
the  basis  or  vehicle  for  receiving  the  colors  and  transferring  them  to  the 
paper,  and  is  placed  in  a  shallow  tank  on  legs;  the  tank  being  about  five 
feet  long,  three  feet  wide,  and  four  inches  deep.  This  body  must  be 
renewed  as  often  as  fermentation  in  the  mucilage  renders  it  liquid  ;  \m 
cold  weather  this  is  not  so  frequent,  but  in  hot  weather  it  must  be 
replaced  with  fresh  at  least  twice  daily.  The  colors  used  are  the 
ordinary -paint  colors,  ground  to  a  cream  with  thin  mucilage  of  gym 
arable.  The  workman,  standing  over  the  tank,  first  takes  a  large  brosli' 
with  spreading  bristles,  and  dipping  it  in  his  color,  sprinkles  it  over  she 
surface  of  the  tank  by  twirling  the  handle  between  his  hands.  The 
value  of  the  mucilage  is  now  shown,  for  the  color  does  not  either  mix 
with  It,  or  spread  over  its  surface,  but  retains  the  circular  form  the  drops 
would  assume  upon  first  striking  a -plane  surface.  The  first  color  is 
then  followed  in  a  similar  manner  by  a  second,  using  a  fresh  brush,  aod 
this  in  turn  by  a  third,  and  so  on  at  the  pleasure  of  the  operator,  eacli 
particular  drop  showing  no  disposition  to  mix  with  its  fellows  The 
pattern  thus  made  is  mostly  of  round  drops,  but  should  it  be  desired  t» 
vary  it,  combs  of  different  degrees  of  fineness  are  drawn  in  differepr 
directions  gently  over  the  surface,  producing  beautiful  wavy  lines  asu^i 
figures.  The  paper  is  now  floated  gently  upon  the  surface  of  the  taok 
for  a  few  seconds,  when  the  color  is  transferred  from  its  surface  to  that 
of  the  paper,  and  after  being  hung  to  dry  is  burnished  by  hot  steel  roS- 
