1309.) 
the centre, had been regarded as a proof 
@f the action of the medicines upon the 
calcuins, aud led to the belief, that 
where te stone was smal] it might be 
wholly dissolved; but it wow appears, 
that-tie soft part is not a portion of the 
sriginal calculus, but a newly-formed sub- 
stance, in which the anc acid is not de- 
posited: in crystals, but mechanically 
mixed with phosphates, and the animal 
mucus in the urive. 
The opioies that calculi in the human 
bladder have been entirely dissolved has 
received its principal support from. in- 
stances having occurred, where the symp- 
toms went entirely away, while the pa- 
tie were using alkaline. medicines, 
8 never afterwards returned. The 
fallacy of this opinion has been detected, 
by examining the subjects after death; 
in one case, the patient was 68, and 
had been tong taking the saline draught, 
when all symptoms vanished, and the 
_ €ase was publistied in proof of its efh- 
cacy; but when he died, 20 calculi 
were found in his bladder ; and it ape 
peared, that the symptoms went off, on 
account of the posterior lobe of the 
prostate gland having become enlarged 
{a change which frequently occurs in that 
period of life), and having formed a bar- 
rier between the calculi and the orifice of 
the bladder, so that they nd longer irri- 
tated that part, either in making water, 
or in the different movements "of the 
body, but lay in the lower posterior part 
of the bladder, without producing any 
painful effects. ‘Their number, (says Mr. 
Home,) prevented the pressure from be- 
ing great on one part of the intestine, 
immediately behind the bladder, and 
their motion on one another rendered 
their external surface smooth, and pro- 
bably prevented their increase. In ano- 
ther case of the same kind, 14 calculi 
were found, which were similarly situ- 
ated by means of the same sort of en- 
Jargement of the posterior gland, In 
some cases calculi have been found en- 
glosed in cysts, formed between the fas- 
ciculi of the muscular coat of the blad- 
der, so as to be entirely excluded from 
the geyeral cavity, and therefore had not 
produced any of the common symptoms 
‘of stone, To prove that calculi do some- 
times increase, while the patient is using 
alkaline medicines, ‘the following facts 
‘are adduced :— 
“A gentleman, having voided a smail 
calculus, persisted i i tie use of alkaline 
medicines, and passed no-more calcul ; 
( 
Proceedings of Learned Socteties. 593 
but on his death, at the age of 75, the 
whole cavity of the bladder was found 
completely full of soft, light, spongy cal- 
culi, 350 in number, They were ana- 
lized, and feund to consist of uric acid, 
the phosphates and animal mucus, and 
differed so much from the calculus voided 
soon after he began the use of alkalies, 
that they appear to have been formed 
after that period, 
Another person, having taken the al- 
kali three menths, finding the symptoms 
sull more violent, submitted to an ope. 
ration. The caleulus, for the thickness 
of th of an inch, was entirely composed 
of. imple phosphate, in a state of perfect 
spiculated crystals, so as to present a very 
rough ‘irritating surface to. the internal 
membrane of the bladder, while the inner 
parts of the calculus were made up of a 
mixture of uric acid and phosphates, so 
that the alkali had prevented the forma- 
tion of uric acid, but the phosphates were 
deposited more rapidly than before. 
A gentleman, in whose urine the uric 
acid appears in a solid form, immediately 
after it is voided, has the same appearance 
in the urine, even when nine drachms of 
soda dissolved in water, impregnated with 
carbonic acid, are taken in 24 hours ; so 
that the alkali does not even counteract 
the formation of uric acid. 
SOCIETY OF ARTS, MANUFACTURES, &e. 
Mr. Waistell has obtained the gold 
medal for his paper on the * Method of 
ascertaining the value of growing umber 
trees, at ite ucdt and distant periods of 
time.” Someaccountot this method will 
be deemed of great importance to ail 
growers of timber, to enable them to as- 
‘certain, the value of timber in all its 
Stages, and to point out to them the most 
proper and profitable time of felling it. 
The author was led to the investigation of 
this subject trom being called to value 
plantations, one of which very much «xe 
ceeded his estimate. Hence he spared 
no pains in collecting all the facts con- 
nected with the subject, and he finds that © 
the increase in the circumference of trees 
is geverally from about one to two inches 
annually; and from 42 to 18 inches the 
annual increase in height, sone fall a lite 
tle short, and some exceed those imea- 
sures. Adopting this, as a well-grounded 
theory, he has constructed a namber ot 
tables which may be useful to practical 
men ; for whom we shall give the first and 
second wih explanations, ™m order that 
our 1gaderg may judge how far the subj ject, 
on ee 
