J 24 Dr. R. D. Thomson's Examinalion of Babingionite,, 



without any authority. Kobell fixes it at 3'i» QU what author-r 



\iy is not mentioned. • Mi^i ^nibajaiq adj "lo 



ui]^Au^ <til<3 Ulpwpip© the crystals ftise per se into a black 



©nam^Jii '■ ft)ili8 



With carbonate of soda they fuse into a green opake bea9 

 in the reducing flame. 



With borax in excess a clear pale yellow bead becoming 

 violet, and with microcosmic salt in excess a clear pale amber 

 bead are formed. ThesQ results are similar to those obtained 

 by Mr. Children, and his conclusions respecting the nature of 

 the constituents of the mineral, by testing, a,re corroborated 

 by analysis, 



The following analysis was mad^ with the carefu) assistance 

 of my friend and pupil, William Parry, Esq., late of the 4^ii 

 King's Own Regiment. 



20*87 grains lost by a red heat 0-26 grs. water, 



•=>'" T9-62 grains gave 9*42 grs. silica, ' "'^ 



amfis . ^ s 3-38 ... protoxide Of iron,'^^'^^^M"^«^ « 



4«oom«^i.x.^.^.;.>.ii;.;2.j^ ^^^ red oxide of manganeS^'"'!!* 

 n«nJ •ladj'td noum o^Ib - • i r- "^f" ™ 



e[!Tfob->ffQa yd 9an ;^t.dJ'Q^ ••• protoxide of manganeSe^,^ j^^^^ 

 ^•oiun ofh" ;>fl^if!<^i hiiH W^. -M , alumma, ^ ^.|^j ^. ^^ 



.'iiinoi^nk]n<l5'!^\,?'mn carbonate of lime, ^.^^^^ ^jg^^ 



vv-cT,>a AnV^'J^ <:v^\ Xc* ^'♦^ ...'^magnesia. \ „;\> .-O'ZX 

 These numbers correspond with the following per-centage 

 composition : — 



I. II. III. IV. 



Coniposition Atomic weights of No. of No. of atoms re.. 

 by expt. the constituents, atoms, duced to lowest 



terms. 



Silica 47-46 2- 23*73 26*36 



Protoxide of iron . . 16*81 4*5 3*75 4*16 



Protoxide of manganese 10*16 4*5 2*25 2*5 



Alumina 6'48 2*25 2*88 S'2-afi 



Lime 14*74 3*5 4*21 4*6 



Magnesia .... 2*21 2*5 0*90 1*0 



Water 1'24 1-125 1*10 1*22 



99*10 



dl 



if is necessary to observe that the manganese contained a 

 minute portion of iron. m-iK r Hi 



The first column gives the r^iiilt&'bf experiment; the second- 

 the atomic weights of the constituents; the third column is the 

 product of the division of the first by the second column ; and 

 the fourth exhibits the product of the division of the number^ 

 in the third column by the lowest term in that column. ""^ 

 I The following Table expresses the theoretical composition 



