304        LIQUOR  POTASS AS  A  SOLVENT  FOR  GUM  RESINS. 
then  ascend  the  Amazon,  to  the  Andes,  and,  finally,  after  ex- 
plorations in  the  mountains,  descend  to  Lima. 
Professor  Agassiz  at  first  intended  only  a  visit  to  Brazil  for 
his  health,  and  proposed  to  take  along  one  or  two  assistants  to 
aid  him  in  making  collections  for  the  Museum  of  which  he  is 
Director  at  Cambridge.  On  mentioning  his  plan  to  Mr.  Na- 
thanael  Thayer,  this  generous  patron  of  science  at  once  said 
"  Agassiz,  go  home,  find  six  assistants,  and  I  will  pay  the  bill." 
The  Pacific  Mail  Steamship  Co.,  hearing  early  of  the  projected 
tour  of  exploration,  immediately  tendered  to  Professor  Agassiz 
and  his  wife  free  passage  to  Rio ;  and,  afterward,  on  learning 
of  Mr.  Thayer's  munificent  proposition,  Mr.  McLane,  in  the 
name  of  the  Director  of  the  Company,  offered  to  the  whole 
party  free  passage  in  the  new  steamer  Colorado,  about  sailing 
for  Panama  via  Cape  Horn.  The  arrangements  were  soon 
completed,  and  within  three  weeks  after  Mr.  Thayer's  promise 
was  made,  the  expedition  left  New  York  in  the  Colorado. 
The  Secretary  of  the  Navy  has  given  Prof.  Agassiz  a  letter 
addressed  to  all  officers  of  the  navy  whom  they  may  meet,  in 
order  to  secure  for  them  free  transportation  when  desired.  He 
offered  also  a  government  vessel  to  take  them  to  their  place  of 
destination  in  South  America,  but  they  were  already  provided, 
through  the  liberality  above  mentioned.  Every  facility  may 
be  looked  for  also  from  the  Emperor  of  Brazil,  who  has  for 
some  time  past  manifested  great  interest  in  the  welfare  of  the 
Museum  of  Comparative  Zoology  at  Cambridge. 
Great  results  may  be  expected  from  an  expedition  under  such 
a  leader,  so  ably  supported  and  so  well  equipped.  The  explo- 
rations will  be  mainly  inland,  and  therefore  the  richer  in  novel- 
ties to  science." — Am,  Jour.  Sci.  and  Arts,  May,  1865. 
LIQUOR  FOTASSJS  AS  A  SOLVENT  FOR  GUM  RESINS. 
Solutions  of  gum  resins  in  liq.  potassse  recommend  them- 
selves for  their  elegance  and  economy,  while  they  are  generally 
very  effective.  For  instance,  a  dilute  solution  of  ammoniacum 
in  water  is  perfectly  clear,  whereas  a  tincture  produces  an 
opaque  mixture.  The  alkaline  solutions  of  aloes,  catechu,  and 
kino  are  very  cheap  and  elegant  colouring  matters,  a  few  drops 
