VARIETIES. 
broken,  as  all  the  pressure  comes  on  the  machine  itself.  It  can  be  carried 
in  the  pocket,  and  is  most  decidedly  an  astonishing  apparatus. — Druggists' 
Circular. 
Green  Varnish. — For  the  production  of  this  varnish,  a  resinous  soap 
must  first  be  prepared,  which  is  easily  done  by  the  following  recipe  ; — 15 
parts  by  weight  of  powdered  colophony  are  stirred  up  with  18  parts  by 
weight  of  water  in  an  iron  pot,  and  heated  to  boiling ;  a  solution  of  2  parts 
of  crystallized  carbonate  of  soda  in  5  parts  of  water  is  then  slowly  added, 
by  stirring,  to  the  mixture,  which  is  again  brought  to  boil.  After  the 
addition  of  a  similar  quantity  of  carbonate  of  soda,  the  whole  is  boiled 
until  all  the  resin  has  disappeared ;  it  is  then  allowed  to  cool,  and  to  be- 
come clear  by  standing.  The  clear  solution  is  mixed  with  an  aqueous 
solution  of  sulphate  of  copper,  as  long  as  a  precipitate  is  produced  ;  this  is 
then  allowed  to  settle,  or  filtered  through  linen.  After  drying,  it  forms  a 
pale  green,  pulverulent  mass,  which  dissolves  readily  in  turpentine,  and 
then  forms  a  beautiful  green  varnish. —  Chem.  Gaz.  from  Polyt.  Centralbl. 
1857,  p.  544. 
Artesian  Wells  in  the  Desert. — The  Moniteur  Algerien  brings  an  inter- 
esting report  on  the  newly  bored  artesian  wells  in  the  Sahara  Desert,  in 
the  province  of  Constantine.  The  first  well  was  bored  in  the  Oasis  of 
Oued  Rir,  near  Tamerna,  by  a  detachment  of  the  Foreign  Legion,  con- 
ducted by  the  engineer,  M.  Jus.  The  works  were  begun  in  May,  1856, 
and  on  the  19th  of  June  a  quantity  of  water  of  4010  litres  per  minute,  and 
of  a  temperature  of  21°  Reaumur,  rushed  forth  from  the  bowels  of  the 
earth.  The  joy  of  the  natives  was  unbounded ;  the  news  of  the  event 
spread  towards  the  south  with  unaxampled  rapidity.  People  came  from 
long  distances  in  order  to  see  the  miracle.  The  Marabouts,  with  great 
solemnity,  consecrated  the  newly-created  well,  and  gave  it  the  name  of 
"the  well  of  peace."  The  second  well,  in  Temakin,  yielded  35  litres,  of 
21°  temperature,  per  minute,  and  from  a  depth  of  85  metres  :  this  well  was 
called  "the  well  of  bliss;"  a  third  experiment,  not  far  from  the  scene  of 
the  second,  in  the  Oasis  of  Tamelbat,  was  crowned  with  the  result  of  130 
litres  of  water  per  minute.  The  Marabouts,  after  having  thanked  the 
soldiers  in  the  presence  of  the  population,  gave  them  a  banquet,  and 
escorted  them  in  solemn  procession  to  the  frontier  of  the  oasis.  In  another 
oasis,  that  of  Sidi-Nached,  which  had  been  completely  ruined  by  the 
drought,  the  digging  of  "  the  well  of  gratitude"  was  accompanied  by 
touching  scenes.  As  soon  as  the  rejoicing  outcries  of  the  soldiers  had 
announced  the  rushing  forth  of  the  water,  the  natives  drew  near  in  crowds, 
plunged  themselves  into  the  blessed  waves,  and  the  mothers  bathed  their 
children  therein.  The  old  Emir  could  not  master  his  feelings;  with  tear 
in  his  eyes,  he  fell  down  upon  his  knees,  and  lifted  his  trembling  hands 
