12 
ON PHOSPHATE OF AMMONIA. 
fibrous tissues into fibro-cartilage, and cartilage into bone. 
And where chemists have examined these structural thick- 
enings, they have found a variable abnormal per centage of 
earthy matter, consisting for the most part of soda and 
lime. Both diseases are frequently associated with what 
is called the uric or lithic acid diathesis ; that is to say, 
when a man has a gouty or rheumatic habit, it is generally 
found that lithic acid is in excess in the secretions of his skin 
and kidneys. When an individual labours under an acute 
attack of gout or rheumatism, his recovery is generally her- 
alded by a redundant deposit of lithic acid in his urine. 
This harbinger of a favourable termination to the disease 
may happen on the second day of his attack, or on the 
sixth week, as may be ; but whenever it does appear, it 
may very safely be said that the patient is convalescent. 
" By what mode this acid is eliminated, or what accident 
it is which determines its separation, we are unable to say ; 
it stands merely as an isolated fact that by some chemical 
or vital change taking place, uric acid is separated in great 
quantity and the individual is relieved. The urine in the 
course of such an attack may be examined and found as 
clear as water, and the fluid passed ten or twenty hours 
after, so loaded with lithic acid as to resemble the washings 
of a wine cask or beer barrel. From whence is this enor- 
mous quantity of lithic acid so suddenly derived? Not 
from any sudden defect of assimilation occurring in the 
course of the disease, or from the solids of the body. It is 
most likely then derived from the blood ; but uric acid can- 
not have existed there in a free state, or it would have been 
passed from day to day. If then it existed in the blood, it 
must have been in some state of combination with soda, or 
lime, or both. And this is the more likely, when we reflect 
that the concretions and thickenings which take place in 
the fibrous, cartilaginous, and white tissues generally, as be- 
fore stated, are owing to the deposit in them of soda and 
lime in variable proportions with lithic acid. Taking into 
