^jiiyXm™'}       Notes  on  American  Asphaltum.  315 
all  travellers  who  have  visited  that  region.  The  asphalt  is  here 
plainly  inspissated  petroleum.  It  drips  from  the  cliffs  at  many  points, 
and  forms  a  scum  on  the  ocean  off  the  coast.  There  it  is  evaporated 
and  oxidized,  then  thrown  upon  the  beach  by  the  waves,  where  it  ac- 
cumulates in  large  masses,  generally  mingled  with  sand  and  other 
foreign  matter.  When  pure,  the  asphalt  of  California  resembles  that 
from  Trinidad,  and  is  beginning  to  be  used  for  the  same  purposes — - 
roofing,  paving,  lining  of  cisterns,  &c.  The  wants  of  the  entire  wes- 
tern coast  can  be  easily  supplied  from  this  source.  About  Chicago,  Il- 
linois, the  Niagara  limestone  is  in  some  localities  completely  saturated 
with  a  thick  petroleum,  which  on  exposure  is  converted  by  evapora- 
tion into  asphalt.  There  are  no  important  asphaltic  accumulations 
here,  and  it  is  perhaps  a  little  doubtful  whether  the  hydrocarbon 
which  fills  the  limestone  is  not  too  oily  to  serve  the  same  purposes  as 
the  bitumen  in  the  limestone  of  Val  de  Travers.  But  I  know  of  no 
asphaltic  limestone  which  approaches  nearer  to  the  foreign  variety 
now  so  largely  used,  and  it  is  quite  possible  that  with  appropriate 
treatment  others  may  be  utilized  in  the  same  way. 
The  above  list  includes  all  the  important  deposits  of  asphaltum  in 
our  country  of  which  anything  definite  is  known.  At  various  points 
in  the  far  west,  occur  what  are  known  as  "  tar  springs,"  really  oil 
springs,  around  which  more  or  less  asphaltum  accumulates  as  the  re- 
sult of  evaporation.  In  Texas,  south  from  Shreveport,  a  pitch  lake 
is  spoken  of,  in  which  are  said  to  occur  large  quantities  of  bitumen. 
But  of  this  almost  nothing  is  known. 
In  anticipation  of  a  great  demand  for  asphaltum  for  the  uses  to 
which  it  is  so  extensively  applied  in  Europe,  I  have  endeavored  to 
ascertain  the  quality  and  quantity  of  all  the  asphaltic  materials  found 
in  our  country,  and  with  the  exception  of  the  Albert  mine,  have  vis- 
ited all  of  the  localities  described  in  the  above  notes.  The  result  of 
my  observations  has  been  the  conviction,  that  aside  from  the  Alber- 
tite  and  Grahamite,  which  from  their  peculiar  character  will  but  par- 
tially supply  our  want  of  asphaltic  material,  we  must  look  to  Trinidad 
as  a  source  from  which  we  are  to  obtain  the  greater  part  of  our  as- 
phalt. The  quantity  existing  there  is  inexhaustible.  The  quality  is 
such  that  it  will  with  proper  treatment  do  all  that  asphalt  will  any- 
where do,  and  it  is  so  accessible  and  transportation  to  our  seaports  so 
inexpensive,  that  it  should  be  furnished  from  this  source  to  our  At- 
lantic cities,  at  a  much  less  price  than  asphalt  brought  from  any  point 
in  the  interior  must  cost. — American  Chemist,  May,  1872. 
