AmASusiPi8£m"}     Notes  on  Some  Saps  and  Secretions.  407 
The  arsenous  acid  being  present  in  practically  ten  times  the 
proper  amount  leads  to  the  suggestion  that  the  error  may  have 
occurred  in  an  attempt  to  translate  from  the  metric  to  the  custom- 
ary system,  in  the  absence  of  a  proper  outfit  of  metric  weights  and 
graduates. 
NOTES    ON    SOME    SAPS    AND    SECRETIONS  USED 
IN  PHARMACY. 
By  P.  L.  Simmonds,  F.L.S. 
[Concluded  from  p.  328.1 
Pinns  species.  Very  many  species  of  Pinns  yield  volatile  oils 
used  in  pharmacy.  Among  others,  P.  palnstris,  Ait,  or  P.  pinaster, 
P.  Tceda,  Pinus  sylvestris,  Lin.,  P.  Pumilio,  Hank.,  the  P.  Mugus, 
Scop.,  and  others. 
Pinus  Abies,  Lin.,  P.  Picea,  Du  Roi,  P.  vulgaris,  Abies  excelsa, 
Dec,  the  silver  fir. — This  species  furnishes  the  oleo-resin  known 
as  Strasburg  turpentine,  which  resembles  common  turpentine,  but 
has  a  more  agreeable  odor. 
P.  balsamea,  Lin.,  Abies  balsamea,  Marshall,  A.  balsamifera, 
Michx  — The  balsam  fir  yields  the  well-known  oleo-resin,  Canada  tur- 
pentine, which  is  exported  from  Quebec  in  kegs  or  large  barrels. 
Canada  balsam  is  used  for  medicinal  and  manufacturing  purposes. 
It  is  an  ingredient  in  blistering  paper  and  flexible  collodion.  It  is 
highly  valued  and  much  employed  as  a  menstruum  for  mounting 
microscopic  objects,  and  makes  a  fine,  transparent  varnish  for  water- 
color  drawings,  which  does  not  become  darker  with  time. 
P.  Australis,  Michx.,  P.  paiustris,  Mill. — This  is  the  most  valuable 
of  all  the  American  pines.  From  it  are  obtained  the  American 
"Thus,"  the  concrete  turpentine,  the  volatile  oil  from  turpentine, 
and  the  resin.  There  are  three  principal  descriptions  of  turpentine 
known  in  commerce,  American,  Bordeaux  and  Russian.  Bordeaux, 
from  P.  pinaster,  Ait.;  Russian,  from  P.  sylvestris,  Lin.;  Chian,  from 
Pistacia  Terebinthus,  Lin. 
P.  Canadensis,  Lin.,  Abies  Canadensis,  Michx.  and  DeC. — The 
hemlock  spruce  furnishes  the  concrete  turpentine  known  as 
Canada  pitch,  which  is  official  in  the  United  States.  It  is  slightly 
stimulant,  like  Burgundy  pitch,  and  employed  for  similar  purposes. 
A  volatile  oil  is  obtained  from  the  leaves,  which  produces  dangerous 
