VARIETIES. 
177 
but  there  were  obvious  objections,  and  a  much  better  vehicle  was 
found  in  soapy  water. 
The  best  white  soap,  sold  at  the  shops,  is  of  the  same  specific 
gravity  as  water,  and  its  mixture  with  water  makes  no  chaDge, 
in  that  respect.  When  the  mixture  is  as  strong  as  children  use 
for  blowing  bubbles  (we  cannot  conveniently  give  this  measure 
in  figures,)  the  cohesion  or  tenacity  of  the  water  is  so  much 
weakened  that  the  drop  is  reduced  to  one-tenth  of  a  grain.  No 
other  fluid  makes  so  small  a  drop  as  this.  And  there  is  the 
further  advantage,  that  soapy  water,  though  excellent  for  mak- 
ing bubbles,  is  less  liable  to  retain  them  below  the  surface  than 
pure  water.  So  small  a  drop,  of  course,  makes  the  experiment 
more  tedious,  and,  by  using  less  soap,  the  size  of  the  drop  will 
be,  in  many  cases,  advantageously  increased.* — Sillimans 
Journal,  Sept.  1856,  from  Proc.  Amer.  Phil.  Soc. 
Observations  on  the  climates  of  California.  By  Mr.  George  Bartlett, 
(from  a  letter  dated  Providence,  June  27, 1856.) — The  natural  forces  which 
produce  the  various  meteorological  phenomena  of  California,  are  much  less 
numerous  than  in  the  eastern  part  of  the  continent,  and  act  on  a  much 
larger  scale,  and  they  are  therefore  more  easily  understood.  In  fact,  -with 
a  knowledge  of  three  great  causes,  the  peculiarities  of  the  several  climates 
of  California  would  have  been  readily  anticipated.  These  are  ;  1st,  the 
cold  ocean  current  which  rolls  along  the  coast  from  northwest  to  southeast ; 
2d,  the  direction  of  the  winds  •  3d,  that  property  of  air  by  which  its  capaci- 
ty for  containing  moisture  is  increased  with  the  elevation  of  its  temperature. 
The  ocean  current  will  no  doubt  be  thoroughly  examined  in  the  course  of 
the  Coast  Survey.  Dr.  Gibbons,  of  San  Francisco,  ascertained  at  one  time 
its  temperature  to  be  54°  Fahrenheit. 
Now,  during  the  summer  months,  as  soon  as  the  rays  of  the  sun  have 
warmed  the  air  over  the  land,  it  becomes  rarified,  and  the  colder  and  hea- 
vier air  rushes  in  under  it  from  the  ocean,  producing  that  sea-breeze,  which 
*£Note. — An  apparatus  precisely  similar  in  principle,  but  varied  slightly 
in  detail,  was  described  and  figured  in  the  Pharmaceutical  Journal  for  May 
1856  by  Mr.  Stevenson.  Instead  of  the  open  spout,  a  tube  depressed  at  an 
angle  furnished  with  a  stop  cock  is  used. — Editor  Amer.  Jour.  Ph;arm.~| 
12 
