
 
        
         
		be  considered to differ essentially from  them.  
 For the  information relative to  their component  
 parts,  I  am  entirely  indebted  to  the  
 skill  and  knowledge of  our celebrated countryman, 
  Mr. Myhlensteth,  who has  had  the  
 goodness  to  make  an  accurate  chemical  
 analysis,  not  only  of  the  various  kinds  of  
 lava,  but  of  the  fine whitish  substance  resembling  
 salt, which  has  been before  mentioned, 
   and also of  various other  substances,  
 one  among  which  deserves  particularly  to  
 be noticed,  a kind  of  ravelings,  which  resembles  
 grey hairs.  This was  to  be  found  
 every where  in  the vicinity  of  the  fire,  but  
 especially  on  level  sandy  places,  an<J  no  
 where in  so great quantity  as  on the  extensive  
 sandy  plain  of  Skeidarasand,  to  the  
 eastward  of  Nupsvaters  and  Fliotshverfet.  
 The filaments sometimes lay spread out singly  
 upon  the  ground;  sometimes  mixed  and  
 interwoven  with  each  other;  in  other  
 places,  twisted  by  the  action  of  the  wind  
 into  the  form  of  garlands  of  various  sizes,  
 or  into  circles  of  a  light  grey  color.  The  
 ravelings  themselves,  though  short  and  
 broken,  resembled  the finest  hair. 
 The  following  is  the result of Mr. Myh-  
 lensteth’s  experiments  upon  the  five  different  
 kinds  of  volcanic  substances  which  
 were sent  to him,  and which have  now been  
 mentioned : 
 No.  1  resembles  externally  the  scum  
 of  iron.  Two  ounces  of  it  being  pulverized, 
   one ounce  of  iron  was  extracted from  
 it,  by means of  the  loadstone,  and  was perceptible, 
   with  a magnifying  glass,  in  small  
 thin laminae,  to  which  some  lava  was  still  
 attached.  These  two ounces  were put  into  
 an equal quantity  of oil of vitriol,  mixed  up  
 with  it,  then  thinned  with  eight  parts of  
 water.  The vitriolic acid evidently  dissolved  
 the  iron,  when  the  solution  was  separated,  
 which,  at  blood-heat,  afforded  a  fine Prussian 
 blue  color.  The  remaining  part,  that  
 was not  dissolved by the  vitriolic  acid,  was  
 thoroughly  dried  and  found  to  have  lost  
 three  quintins  of  its  weight,  and  the  loadstone  
 had no effect upon it.  Another experiment  
 was tried with one ounce of this mineral,  
 from  which the  magnet  only  extracted  one  
 and  a  half  quintin,  and  the  vitriolic  acid  
 ° dissolved only  twenty-four  grains of it.