Intelligence and Miscellaneous Articles. 461 



the air it becomes quickly yellow, and so also does the solution. It 

 is very soluble in water. 



Digitalate of Potash. — Obtained by decomposing the carbonate in 

 the same way as the preceding. It crystallizes with difficulty and is 

 very soluble in water. 



Digitalate of Magnesia. — Obtained from the acid and carbonate of 

 magnesia ; soluble in water. 



Digitalate of Barytes. — Obtained by saturating the acid either 

 with barytes or the carbonate. It is soluble in water, but insoluble 

 in alcohol and in aether. Quite colourless, but by exposure to air 

 and heat it becomes brown. 



Digitalate of Lime is obtained in the same way as the barytic salt, 

 with which it has great analogy ; being insoluble in alcohol and in 

 aether, it may be employed for the preparation of digitalic acid. 



Digitalate of Zinc. — Obtained by treating the carbonate with digi- 

 talic acid ; the filtered solution is to be evaporated by the air-pump 

 vacuum. 



This salt is formed notwithstanding an excess of carbonate. It 

 is obtained at first as a transparent salt, having the appearance of a 

 thick solution of gum ; but after some days a number of small ar- 

 borescent crystals are formed. This salt does not so quickly become 

 yellow by exposure to the air as those previously described. 

 Digitalate of Lead. — A white, heavy, insoluble salt. 

 Digitalate of Copper. — A greenish, soluble salt. 

 Digitalate of Silver. — A white salt, insoluble in water, but soluble 

 in nitric acid. 



A solution of digitalate of soda gives, with protosulphate of iron, 

 an abundant flocculent precipitate ; with the peracetate of iron it 

 produces no effect ; these reactions prove, according to the author, 

 that digitalic acid cannot be mistaken for gallic acid. 



This acid exists, probably, uncombined with digitalia, for after 

 having treated the watery extract with alcohol, an abundant brown 

 precipitate is obtained, which is devoid of bitterness, but possesses 

 an acid reaction, and digitalic acid may be obtained from it. 



M. Morin observes, that the peculiar properties of digitalic acid, 

 as such, appear to him to be sufficiently established ; though it may, 

 he states, be objected, that it is formed under the influence of the 

 substances, especially of barytes, employed to obtain it ; but to this 

 objection it is replied, that the juice of the digitalis possesses an 

 acid reaction as soon as it is procured ; that the dry leaves treated 

 with water, alcohol, or aether also yield acid solutions ; if the alco- 

 holic or rethereal solution, obtained during the preparation of the 

 acid, be saturated with oxide of lead, the liquor remains bitter, and 

 a precipitate is formed ; if this be washed in the water and alcohol, 

 and then treated with hydrosulphuric acid, the excess of which is to 

 be expelled, a very acid solution is obtained, from which digitalic 

 acid is obtained by crystallization. This process the author thinks 

 may, perhaps, be better than that which he has described, unless it 

 be wished to obtain the bitter principle at the same time ; in this 

 case the action of the base employed is not sufficiently energetic to 



