Am.  Jour.  Pharm.  "I 
June,  1875.  j 
Preparation  of  Urea. 
273 
to  spend  under  water  depends  on  natural  capacity,  age  and  training  ; 
sixty  seconds  time  is  reckoned  good  work — in  rare  instances  eighty 
seconds  are  spent  under  water.  The  Syrian  diver  uses  a  heavy  stone 
to  carry  him  quickly  to  the  bottom,  and  is  drawn  up  by  a  comrade. 
On  the  bottom,  he  holds  the  guide  rope  with  one  hand  and  tears  ofF  the 
sponges  with  the  other,  placing  them  in  a  net  which  he  carries.  No 
knife,  spear  or  instrument  of  any  kind  is  used  in  detaching  the  sponges  ; 
nor  does  he,  like  his  Greek  competitor,  ever  use  the  diving  dress,  hav- 
ing an  antipathy  to  it  on  the  score  of  its  reputed  tendency  to  produce 
paralysis  of  the  limbs.  Two  or  three  fatal  accidents  occur  annually, 
mainly  among  the  skillful  and  daring,  who  sometimes  drop  the  rope  to 
secure  a  tempting  prize,  and  missing  it  on  their  return,  attempt  to  rise 
to  the  surface  unaided,  and  are  drowned.  At  other  times  the  driver 
will  be  wounded  by  jagged  rocks,  or  his  rope  will  become  entangled, 
exposing  him  to  great  risks  where  the  depth  is  great. 
Though  varying  much  in  quality  and  size,  the  sponges  are  roughly 
divided  into  three  classes  :  (i)  The  fine  white  bell-shaped  sponge, 
known  as  toilet  sponge  ;  (2)  the  large  reddish  variety  called  bath  sponge  ; 
(3)  the  coarse  red  sponge  used  for  household  purposes,  carriage  clean- 
ing, etc.  Two-thirds  of  the  produce  of  the  Syrian  coast  are  purchased 
by  native  merchants  for  exportation,  while  the  remaining  third  is  pur- 
chased on  the  spot  by  French  agents.  France  takes  the  bulk  of  the 
finest  qualities.  One-tenth  the  price  received  by  the  finders  goes  to 
the  government  for  revenue. 
It  is  possible  that  this  high-priced  and  durable  variety  of  sponge 
might  be  cultivated  in  our  southern  waters,  as  a  substitute  for  the  beau- 
tiful but  tender  sponge  they  now  yield.  The  experiment  would  be 
worth  trying. — Scientific  Jmer.^  April  3^,  1875. 
PREPARATION  OF  UREA. 
BY  J.   E.   LOUGHLIN,   M.  D. 
Many  methods  have  been  devised  for  the  preparation  of  urea.  The 
substance,  first  discovered  by  Rouelle  in  1777,  was  clearly  described 
and  named  by  Fourcroy  in  1799.  The  urine  previously  filtered  is 
treated  with  commercial  nitric  acid  (in  the  proportion  i  ounce  nitric 
acid  to  20  ounces  urine),  and  allowed  to  evaporate  spontaneously,  the 
nitrate  of  urea  separates  from  the  urine  in  the  form  of  blackish-red  scales, 
which  are  removed  and  dried  by  pressing  between  folds  of  common 
18 
