420 Dr. Kane's RemarJcs on the Compounds derived 



we find that out of his six analyses, the carbonic acid was 

 lost in one, and the water in two instances; probably from 

 a too rapid and imperfect process of combustion. Mr. Wal- 

 ter's formula is therefore disproved by his own analyses, 

 which give too much carbon and too little hydrogen ; but they 

 agree very well with the formula I proposed, if we allow his 

 analyses to have been of the average degree of excellence. 



The specific gravity of the vapour of the stearopten fur- 

 nishes no test whereby to distinguish between the formulae; 

 C20 H20 Og gives 5*455, and Cgi H20 O.^ gives 5*666. He ob- 

 tained 5*62. It is true, the experimental density generally 

 comes out a little higher than the calculated density ; but on 

 the other hand, with these oils there is almost universally a 

 trace of decomposition by which the experimental density is 

 thrown too low. Hence the density found agrees with one 

 formula as well as the other. 



Mr. Walter has given the name of menthene to a hy- 

 drocarbon, produced by the action of dry phosphoric acid 

 on the stearopten. To this body he assigns the formula 

 C.20 Hj8 : his results are, 



I. II. III. Theory. 



Carbon 87*74 87-53 87*59 87-18 



Hydrogen... 12*99 12*85 12*71 12*82 



100*73 100-3S 100-30 100-00 



In every case Mr. Walter obtained an excess of weight 

 which must be an error in the hydrogen, and in every case 

 the hydrogen increased by this error comes only to about 

 equal the hydrogen required by his formula. In every case 

 also he obtained too much carbon, and this with a substance 

 Avhose perfect combustion must evidently to every organic 

 chemist be most difficult. His formula cannot be true : but 

 the formula Cgi H^g gives the following numbers : — 



Ci = 128*9 87-76 



Hj8 = 18 12-24 



146-9 lOO-OO 



coinciding perfectly with the analyses. 



The density of the vapour of menthene Mr. Walter found 

 to be 4*95. The formula Coj, Hjg gives 4-835. The formula 

 Co] Hjg gives 5*046. The difference here also is so very 

 trifling that no stress can be laid upon it one way or the 

 other. 



The results obtained by the action of sulphuric acid, not 

 being definite, do not require notice, further than to mention 



