AND ON THE INTRODUCTION OF DECOMPONENTS INTO THE BLADDER. 11 
of lead was prepared. From this, saccharic acid and super-saccharate of lead were 
obtained by the aid of sulphuretted hydrogen, as described when speaking of the 
malates of lead. Saccharic acid, however, unless concentrated, exerted no greater 
influence on phosphatic concretions than malic acid ; the neutral saccharate of lead 
was likewise inert, whereas the supersalt proved so active, and yet so mild, that 
it seemed better calculated than any agent hitherto tried, to fulfil the prescribed 
conditions. But as the sulphuretted hydrogen process was tedious and unpleasant, 
Thenard’s statement as to the solubility of the malate in acetic acid was applied to 
the saccharate of lead : a preparation of this kind seemed the more likely to answer 
from its similarity to the cidre-aigre solution. 
An aceto-saccharate was, in the first instance, formed according to Berzelius’s 
directions* *; but as this process was likewise somewhat elaborate, I endeavoured to 
abbreviate it as follows : — Five parts of saccharate of lead, and the same number of 
minims of strong acetic acid, were added to a fluid ounce of distilled water, which 
was gently heated for a short time ; a small quantity of the lead salt was thereby 
dissolved, not more than half a grain. This solution, although perfectly tasteless, 
acted speedily and with energy on any phosphatic fragment of calculus suspended in 
it. The solution on the most careful evaporation yielded no crystals, but was con- 
verted by heat into a viscous syrup, which ultimately became a species of caramel. 
The liquid, therefore, although available for experimental, was not sufficiently definite 
for practical purposes. But as Liebig mentions no less than three definite com- 
pounds of oxide of lead with saccharic acid, I did not despair of succeeding in the 
formation of a salt, such, in all respects, as 1 required. u L’acide saccharique,” says 
Liebig, “ est tres remarquable par le grand nombre de combinaisons qu’il forme avec 
les bases.” 
It now became my object to form an acid saccharate of lead, which was accom- 
plished thus : — a portion of pulverized saccharate of lead was dissolved in a sufficient 
quantity of cold dilute nitric acid'f~. The solution, after being filtered, and gradually 
evaporated, yielded a quantity of perfectly transparent, amber-coloured crystals, in 
the form of regular hexagonal plates or prisms. I have reason to believe that the 
colour is essential to the salt, for when I endeavoured to purify it by re-solution in 
dilute nitric acid, although it still formed hexagonal crystals, the salt had lost its 
activity as a decomponent. 
One grain of this salt, which I shall call nitro-saccharate of lead, moistened with 
commences, and then instantly removing the spirit-lamp. The fumes continue to be disengaged for some time, 
and when they have entirely ceased, decomposition by lime, and precipitation by acetate of lead may ensue. 
* “ Quand on chauffe,” says he, “ un melange d’acide acetique et de saccharate calcique dissous, et qu’on 
ajoute ace melange de 1’ acetate d’oxyde de plomb jusqu’ ace quele precipite commence a ne plus se redissoudre, 
le sel ecailleux cristallise en plus grande quantite par le refroidissement.” These crystalline scales, moistened 
with acetic acid, and dissolved in water, form a good decomponent, 
t One acid to nineteen water. 
