j^Zjf'}  Chemical  Notes,  1 7 
material,  or  of  sulphurous  acid  vapors,  produced  by  burning  about  200 
grams  sulphur  for  the  same  weight  of  raw  material.  The  latter  is  then 
rinsed  off,  and  the  portion,  intended  as  a  substitute  for  isinglass,  deprived 
of  the  outer  skin,  dried  at  a  moderate  heat  and  pressed,  while  the  por- 
tion intended  for  gelatin  or  glue  is  exposed  for  about  10  or  12  hours 
to  a  heat  of  from  40  to  50°C.,  when  the  greater  portion  is  dissolved  ; 
it  is  then  forced  through  a  strainer  or  sieve  and  dried. — Pharm. 
Handehb:^  Nov.  5,  1879,  p.  45. 
New  Mineral  Gum. — This  gum  is  reported  to  be  an  excellent  sub- 
stitute for  gum  arabic,  glue,  etc.,  and  to  make  an  excellent  cement  with 
gypsum,  and  consists  of  a  solution  of  aluminium  phosphate  in  sulphuric 
or  phosphoric  acid.  It  is  said  to  be  made  by  moistening  380  pounds 
rodondo  phosphate  (?)  with  15  gallons  of  water,  adding  10  gallons  of 
sulphuric  acid,  specific  gravity  i-6,  previously  diluted  with  35  gallons 
of  water  ;  boiling  the  mixture  for  several  hours,  then  filtering  by  means 
of  a  Needham's  press,  concentrating  the  solution,  adding  a  little  more 
phosphate  while  concentrating,  and  removing  an  excess  of  acid,  if  pres- 
ent, by  lime. 
If  phosphoric  acid  is  used  instead  of  sulphuric  acid,  it  is  made  by 
the  action  of  sulphuric  acid  on  bone-dust. — 7^/V.,Nov.  5,  1879,  p.  45. 
CHEMICAL  NOTES. 
By  Prof  Samuel  P.  Sadtler. 
Inorganic  Chemistry. —  On  a  new  Method  of  Preparing  Hydrohromic 
and  Hydriodic  Acid  Gas. — G.  Bruylants  has  sought  to  avail  himself  of 
the  fact  that  bromine  and  iodine  combine  at  ordinary  temperatures  with 
many  organic  bodies,  and  under  the  influence  of  heat,  escape  as  hydro- 
hromic or  hydriodic  acid  gases,  in  preparing  these  gases  for  use.  Of 
different  organic  bodies  tried  he  finds  that  oil  of  copaiba  works  most 
readily,  giving  up  almost,  if  not  quite,  all  the  bromine  or  iodine  in  the 
form  of  hydrogen  bromide  or  iodide.  The  oil  should  distill  at  250*^  to 
255°C.,  and  should  be  previously  dried  over  calcium  chloride.  Some 
50  per  cent,  of  such  oil,  or  even  at  times  80  per  cent.,  may  be  gotten 
from  the  copaiba  balsam.  A  given  amount  of  this  oil  will  convert 
three  times  its  weight  of  bromine  or  iodine  into  the  corresponding 
hydrogen  compound  :  60  grams  of  oil  were  taken  and  placed  in  a 
2 
