198 Dr. Stenhouse on Meconic and Komenic Acids. 



This salt therefore is bibasic with 2 atoms water, and its 

 formula is Ci2H208 + 2PbO + 2aq=KO + 2PbO + 2aq. 



The same salt is also formed when komenate of ammonia 

 is dropt into a solution of acetate of lead. Komenic acid ap- 

 pears therefore to form only one lead salt. This result is 

 rather unexpected, as when komenic acid is neutralized with 

 ammonia it forms a second silver salt. 



The salt made from acetate of lead and komenate of am- 

 monia was also analysed. 



I. 0*5615 grm. of salt gave 0*2025 of metallic lead and 0*1 1 1 

 of oxide = 58*61 per cent, oxide. 



II. 0*874-5 grm. of salt gave 0*2075 of lead and 0*29 oxide 

 = 58*72 per cent, oxide. 



Komenate of Copper. 

 When a hot solution of komenic acid is added to sulphate 

 of copper it changes its colour from blue to dark green, and 

 after standing a few minutes, a crystalline precipitate, of the 

 colour of Schweinfurth green, is slowly deposited. The 

 crystals, though small, are very distinct; they are elongated 

 pyramids of a bright green colour, but the colour of their 

 powder is much lighter. When dried at 212° F.: — 

 I. 0*35 gr. of salt gave 0*117 oxide = 33*42 per cent. 



II. 0*2865 0*0955 ... = 33*33 ... 



33*37 mean. 



I. 0*4204' grm. of salt burned with oxide of copper gave 

 0*4664 carbonic acid and 0*0685 water. 



II. 0*4636 grm. of salt gave 0*5225 of carbonic acid and 

 0*0775 water. 



At. Calculated numbers. Per cent. 



12 Carbon . . . 917*22 31*00 

 8 Hydrogen . . 49*918 1*68 

 10 Oxygen . . . 1000*000 33*81 

 2 Oxide of copper 991*400 33*51 

 2958-538 100*00 

 This is evidently a bibasic salt with two atoms of water. 

 Its formula is KO + 2CuO + 2 aq. 



When komenate of ammonia is employed instead of ko- 

 menic acid the same salt is also formed, but it then falls as a 

 copious flocculent precipitate of a greenish yellow colour. 

 0*5507 grm. of salt gave 0'184 of oxide =■ 33*41 per cent. 



Komenic acid also changed a solution of acetate of copper 

 to a green colour, but produced a very scanty precipitate. 

 The addition of ammonia did not increase the quantity of the 

 precipitate, but gave the solution a rich blue colour. 



