VARIETIES. 
79 
On  Crystals  from  the  Sea-Coast  of  Africa.  By  J.  Pearsall. — The  crys- 
tals here  shown  were  obtained  by  Captain  Mitchell,  of  the  merchant  ship 
"  Frankfield,"  while  searching  the  coast  of  Africa,  between  Saldanha  Bay 
and  the  island  of  Ichaboe,  for  guano  deposits.  The  crystals  are  of  carbon- 
ate of  lime,  enclosing  sand  ;  15  to  20  per  cent,  of  sand  is  obtained  from 
some  specimens.  The  crystals  are  very  hard,  and  have  sharp  cutting  edges, 
so  as  to  make  it  a  painful  task  to  walk  upon  them.  The  beach  was  covered 
with  crystals  to  the  extent  of  miles  ;  about  three  miles  was  walked  over,  but 
it  seemed  as  far  as  the  eye  could  reach,  and  was  one-half  to  one  mile  in 
breadth.  Some  of  the  specimens  are  from  4  to  5  inches  in  length,  and  with 
surfaces  showing  a  thickness  of  J  an  inch,  and  from  2  to  3  inches  across  the 
plane.  The  report  given  was  that  some  of  the  crystals  protruded  up  from 
the  sands  so  far  as  to  wound  the  ankles  and  legs  without  great  care  in  walk- 
ing over.  Some  crystals  seem  to  be  opake,  with  the  sand  enclosed  except 
at  the  edges  ;  15  to  20  per  cent,  of  sand  is  obtained  from  portions  of  crystals. 
Carbonate  of  lime  and  magnesia,  with  small  quantities  of  saline  matter, 
common  salt  principally,  can  be  obtained  by  breaking  them  up  in  distilled 
water.  They  are  entirely  soluble  in  diluted  nitric  acid.  Mineralogists  and 
chemists  are  perfectly  well  aware  of  the  stony  substance  called  Fontaine- 
bleau  sandstone,  where  the  sandstone  is  found  having  forms  of  crystals  of 
carbonate  of  lime.  The  crystals  now  exhibited  show  the  grains  of  sand  of 
the  beach  enclosed,  without  altering  the  general  form,  and  also  that  the 
crystal  has  at  its  base  adapted  itself  to  the  sand  and  other  crystals. —  Chem. 
Gaz,  Nov.  1853,  from  Athenceum. 
Telegraphic  Progress.— The  Magnetic  Telegraph  Company  effected  their 
communication  between  England  and  Ireland  on  Monday  week,  when 
their  new  cable  between  Donaghadee  and  Portpatrick  was  successfully  laid 
down. 
The  prospectus  has  been  issued  of  an  association,  under  the  title  of  the 
Mediterranean  Electric  Telegraph  Company,  formed  with  the  object  of  unit- 
ing Europe  with  Africa,  the  East  Indies,  and  Australia,  by  way  of  France, 
Piedmont,  Corsica,  Sardinia,  Algeria,  and  Egypt.  The  route  is  said  to  have 
been  carefully  surveyed.  The  company  are  making  arrangements  for  the 
construction  of  a  subterranean  line  along  the  coast  of  Africa,  from  Algeria  to 
Alexandria ;  and  with  the  aid  of  the  British  Government  and  the  East  India 
Company,  the  wires  may  be  prolonged  across  the  Desert,  the  Red  Sea,  Arabia, 
and  Persia,  to  meet  the  great  Indian  line  of  3000  miles,  now  in  course  of  con- 
struction by  the  East  India  Company,  and  which  may  eventually  be  ex- 
tended to  the  Australian  colonies.  The  capital  is  300,000/.  in  30,000  shares, 
of  10/.  each,  deposit  41.  per  share.  The  Government  of  France  is  said  to  have 
guaranteed  interest  on  180,000/.  and  that  of  Sardinia  on  120,000/.  A  contract 
has  been  entered  into  for  the  complete  execution  of  the  works  from  Spezzia 
to  Tunis,  including  all  preliminary  expenses,  and  a  transfer  of  the  conces- 
sions, with  exclusive  privilege  for  fifty  years,  for  the  sum  of  300,000/.,  the 
amount  on  which  interest  has  been  guaranteed.    The  works  are  said  to  be 
