REMARKS  ON  GUM  MESQUITE. 
223 
by  wholesale  dealers  to  increase  their  profits,  or  to  enable  them 
to  undersell  their  neighbors.  It  is  a  well  ascertained  fact  that, 
in  New  England,  distillers  of  oil  of  tansy  have  been  in  the  habit 
of  introducing  a  large  quantity  of  hemlock  twigs  and  leaves 
(Abies  canadensis)  into  the  still  before  putting  in  the  tansy  and 
water,  and  thus  produce  an  oil  in  which  the  common  oil  of  hem- 
lock forms  the  larger  proportion.  The  great  difference  of  various 
samples  of  oils,  apparently  from  first  hands,  leads  to  the  belief 
that  this  species  of  rascality  is  not  confined  to  the  oil  named. 
As  the  dispensing  pharmaceutists  throughout  the  United  States 
are  deeply  interested  in  this  subject,  they  will  greatly  oblige  us 
by  sending  us  information  bearing  on  the  production  or  trade  in 
volatile  oils,  whether  relating  to  a  single  oil  or  to  several,  and  in 
regard  to  the  processes  or  habits  of  manufacturers,  or  the  adul- 
terations of  dealers,  for  all  which  due  credit  will  be  given  to  the 
writers. 
REMARKS  ON  GUM  MESQUITE. 
By  the  Editor. 
In  our  number  for  January,  we  published  an  article  on  gum 
mesquite  as  brought  into  notice  by  Dr.  G.  G.  Shumard,  in  which  an 
account  of  its  chemical  characteristics  are  given.  In  Silliman's 
Journal  for  March  Dr.  Campbell  Morfit,  of  Baltimore,  has  pub- 
lished a  notice  of  the  same  substance  from  which  we  extract  the 
following  : 
"  The  specific  gravity  of  the  gum  was  1-5 ;  but  this  determination  may 
possibly  admit  of  correction  upon  purer  samples  than  were  disposable 
for  the  experiment. 
Its  proximate  composition  was  found  to  be, — 
Water         .  11.640 
Foreign  matters    .       .       .  0.236 
Bassorin      .-              .       .  0.206 
Arabin        ....  84.967 
Ash            ....  3.000 
100.049 
Cerasin  was  also  sought,  but  not  found.  The  ash  was  estimated  by 
burning  a  given  quantity  in  an  atmosphere  of  oxygen,  and  weighing  the 
residue. 
The  ultimate  analysis,  made  also  by  effecting  combustion  of  the  care- 
fully dried  gum  in  oxygen  gas,  yielded,  in  two  separate  experiments,  the 
following  numbers  : — 
