192  PEor.  j.  w.  .trim  ox  inclusions  or  iektiakt  [May  1S93, 
the  )  unctions  of  the  two  sets  of  igneous  rocks,  and  the  result  he 
arrived  at.  after  a  very  able  and  candid  discussion  of  the  whole 
question,  was  that  the  gabbros  were  erupted  afur  the  granites.1 
In  lb 71.  Prof.  Zirkeh  after  examining  the  rocks  both  in  Skye  and 
hi 'hi.  came  to  the  same  conclusion.* 
Between  the  years  1570  and  1574  I  repeatedly  examined  the 
junctions  between  the  two  rocks,  and  found  that  there  was  abun¬ 
dant  evidence  in  support  of  the  conclusions  published  by  my  pre¬ 
decessors  in  the  same  held,  while  I  failed  totally  to  discover 
any  facts  which  were  opposed  to  those  conclusions.  Consequently  ,  in 
mv  interpretation  of  the  structure  of  the  district.  I  adopted  the  same 
views  as  to  the  relative  ages  of  these  rocks)  as  those  which  had 
been  already  announced  by  Porbes  and  Z i.rkel.s 
In  15vr  Sir  Archibald  Geikie  published  a  memoir  in  which,  while 
abandoning  many  of  his  previous  conclusions  on  the  subject,  and 
adopting  in  their  place  the  views  I  had  put  forward  in  1574,  he 
nevertheless  strongly  maintained  that  all  previous  observers  had 
been  mistaken  as  to  the  relative  ages  of  the  acid  and  basic  rocks, 
and  that  the  granites  are  really  \io\'.n<jer  than  both  the  basalts  and 
gabbros  of  the  district.4  He.  indeed,  went  much  further  than  this, 
and  intimated  that  the  opposite  opinion  arrived  at  by  his  prede¬ 
cessors  was  not  only  one  for  which  there  was  no  foundation,  but 
could  be  maintained  only  by  those  who  had  not  properly  examined 
the  evidence. 
In  his  recent  Presidential  Address  to  this  Society,  the  Pireetor- 
General  of  the  Geological  Survey  has  forcibly  reiterated  these 
conclusions,  and  has  summed  them  up  in  the  following  words : — 
**  There  can  be  no  doubt  that  they  "  (?.  e.  the  granites  and  other 
acid  erup fives!  **  are  the  last  of  all  the  Tertiary  volcanic  series, 
except  the  latest  basalt-dykes  which  traverse  them."  : 
I  cannot,  perhaps,  better  indicate  how  absolutely  crucial  is  this 
question  of  the  relative  ages  of  the  granite  and  the  gabbro,  with 
respect  to  the  two  interpretations  that  have  been  given  of  the 
structure  of  the  district,  than  by  qnoting  the  remarks  on  the  subject 
made  bv  Prof.  A.  H.  Green.  In  an  article  which  claims  to  be  a 
perfectly  impartial  statement  of  the  ease,  and  which  no  one  who 
reads  it  can  possibly  tax  with  undue  leanings  to  my  own  side  of 
the  controversy,  we  And  the  following  passage  : — 
••  So  far  then  the  views  of  Hr.  Geikie  and  Prof.  Judd  may  admit 
of  modifications  vrhick  render  them  less  conflicting  than  they  seem 
a:  first  sight.  But  there  is  one  point  on  which  reconciliation  is 
impossible,  viz.  the  nature  and  relative  date  of  the  eruptions  of  acid 
composition.  Prof.  Judd  recognizes  not  only  acid  eruptions  of  the 
1  ■  botes  on  the  Topography  and  Geology  of  the  Cueliullm  Hills,  etc..'  Edinb. 
bew  Pkik  Journ.  vol.  si.  (ISM)  pp.  7G-99. 
-  •  Geologisehe  Skizxen  son  der  Wesfckiiste  Sehottlands.’  Zeitsckr.  d.  Deutscb. 
GeoL  GesetLsek.  vol.  xxiii.  1571  pp.  1-114. 
•  C  nan.  ■Journ.  GeoL  Soe.  rol.  sxs.  (1874)  p.  14 9. 
4  ■  The  History  of  To  came  Action  during  the  Terriary  Period  in  the  British 
Ides,’  Trans.  Boy.  Soe.  Edinb.  vol.  xsat.  pp.  21-154. 
-  Tuan,  Journ.  GeoL  Soe.  voL  xlviii.  (1892)  Proc .  p.  1G7. 
