288 0/2 the Maimer of separating [Oct. 



present. The solution of manganese in muriatic acid is even 

 precipitated by the oxalates when diluted with a much greater 

 proportion of water ; but the precipitate does not so speedily 

 make its appearance. 



These experiments proved that Dr. John had been deceived ; 

 but Bucholz wished farther to ascertain if the oxalate of iron 

 was as insoluble in all states as Dr. John had alleged. For this 

 purpose he made the following experiments : — 



He took one part of the red muriate of iron which had been 

 suffered to run into deliquescence in the open air, but in a state 

 as neai-ly neutral as possible. He diluted it with 37 parts of 

 water, and added -±- of neutral oxalate of potash dissolved in 8 

 parts of water. The precipitate fell much more slowly than 

 when manganese was employed. To observe the phenomena 

 the better this experiment was repeated in the following manner: 

 One hundred and twenty grains of the same muriate of iron 

 were mixed with an ounce of water, and with an ounce of a 

 solution which contained 80 grains of oxalate of potash, and 

 this mixed liquid was placed in a quiet place. Not a single cloud 

 appeared in the liquid ; it merely assumed a brownish green 

 colour, and remained in that state for eight days without under- 

 going any alteration. Another ounce of the solution of oxalate 

 of potash was then added. The liquid then assumed a deeper 

 brown colour, and in a short time became muddy, by the pre- 

 cipitation of a lemon yellow powder. When this powder was 

 precipitated there gradually formed, in the course of six hours, 

 small crystals of a fine apple-green colour. These crystals 

 formed upon the surface, and were precipitated to the bottom 

 of the liquid. They continued to form during four days, while 

 at the same time a very small quantity of the yellow precipitate 

 attached itself to the vessel in the form of a crust. The liquid, 

 which had still a greenish yellow colour, was decanted. It 

 continued to deposit some green crystals during 15 days, but it 

 was not entirely freed from iron. Having subjected these 

 products to analvsis, M. Bucholz ascertained that the yellow 

 powder was oxalate of iron, and the green crystals a triple 

 compound of potash, oxalic acid, and red oxide of iron. 



Thus it was demonstrated that the process of Dr. John was a 

 bad one; but to leave nothing undetermined M. Bucholz made 

 the following experiment: He mixed together equal portions of 

 muriate of iron and muriate of manganese, dissolved the 

 mixture in 32 times its weight of water, and poured into the 

 solution neutral oxalate of potash dissolved in eight times its 

 weight of water. There appeared at first a slight precipitate of 

 a yellowish white colour, containing obviously much more oxa- 

 late of manganese than oxalate of iron ; • but this precipitate, 

 as it increased in quantity becoming always more and more 

 yellow, was in a short time much richer in iron than in manga- 



