OBSERVATIONS UPON BLAUD's PILLS. 
59 
potassa and the altheine of the marsh mallows. This renders 
it objectionable. 
To recapitulate. The best mode of making Blaud's pills 
consists in pulverizing the two salts together in an iron mortar, 
beating them until they shall be completely divided and 
mixed, adding to them half a drachm of gum tragacanth, and 
allowing the mass to solidify. Then the necessary quantity of 
water is added to give to it the suitable consistence to be 
divided into pills. But we may remark, that the pills as 
directed by Dr. Blaud, weigh more than 12 grains, and that 
their size is an objection to their administration . I think that 
they ought to be reduced to half the volume, that is to say, 
make 96 instead of 48. Two may then be taken in place 
of one, 
M. Soubeiran, in his Traite de Pharmacie, has modified 
Blaud's formula in the way I have proposed, but I do not 
understand the object of assuming the number directed. His 
formula is: one ounce and seven drachms, or fifteen drachms of 
each of the salts, and a drachm of gum arabic, divided into 298 
pills. According to Dr. Blaud, this mass should furnish 180 
pills; in my opinion 360; the medium number will be 270. 
I cannot see the reason for adopting so irregular a number 
as 298. 
I shall make another charge against M. Soubeiran; it is of 
having stated that Blaud's pills contain an excess of sulphate of 
iron which is not decomposed by trituration, and of having 
supposed, as a consequence, that there was formed a double 
sulphate of potassa and peroxide of iron. There can be no 
doubt as regards the carbonate of potassa employed, as M # 
Soubeiran directs the dry salt. 
Now, as I have previously shown, the atomic weights of 
the crystallized sulphate of iron, and dry carbonate of potassa, 
being respectively 1615 and 866, it follows that 866 parts of 
the last are sufficient to decompose completely 1615 of the 
other, and that when equal parts are employed, there remains 
almost half of the carbonate in excess. To be more exact: 
of the four drachms of carbonate in the formula of Dr. Blaud, 
