634 
REVIEWS. 
Again, when speaking of fragilitas ossium he remarks, 
“The case related at page 170—the one we have just quoted 
—goes to prove that the two conditions are quite distinct in 
the horse, as in that case there was simply removal of the 
earthy constituents, rendering the bones flexible and easily 
cut with the knife. I contend that this is the true mollities 
ossium; whereas in the disease now under consideration fatty 
material is substituted for the cartilaginous basis, without 
removal of the earthy matter, and in this way the bones are 
rendered brittle, and liable to fracture from inappreciable 
causes. 5 ’ Professor Williams gives us what he considers as 
the distinctive differences existing between these several 
diseases, and from the number of cases he quotes he has suc¬ 
ceeded in drawing the line of demarcation as distinctly, if 
not more so than most who have already attempted it; still, 
notwithstanding this, and the special attention which has 
been bestowed on these diseases by Solly, Curling, Stanley, 
MacIntyre, and Rokitansky, we think there is even yet good 
grounds for viewing the question of their several distinctive 
differences, and the relations which they bear to each other, 
as scarcely so well determined as could be desired. 
The subject of lameness with diseases and injuries of the 
feet occupies ten chapters. Our professional records, which 
may be said to be wonderfully rich on these subjects, have 
been liberally drawn upon, the sources faithfully acknow¬ 
ledged, and the conclusions justly stated. Amongst the 
members of the profession we think there will he little differ¬ 
ence of opinion as to the expediency of classing as unsound¬ 
ness the various affections which in these several chapters 
receive attention. On the pathology of some, however, and 
notably that of navicular disease, we suspect the same cannot 
be affirmed. 
In speaking of the subject of lameness, the following ob¬ 
servations on the curative action of external irritants are 
deserving of attention :—“ I am of opinion,” he says, “ that 
the curative action of externalirritants is not due to their pro¬ 
ducing metastasis on counter-irritation, but that they excite 
within the originally diseased structure a reparative inflam¬ 
mation, partaking in its nature of what is described Virchow by 
as the secretory inflammation, which, superseding the original 
diseased process (whether that be inflammation pure and 
simple or its effects—ulceration, caries, or the formation of a 
low form of fibrous tissue), excites {he formation of reparative 
material by which breeches are united, ulcers healed, and 
diseased action removed.” 
Of tumours, malignant and benign, we have an accurate 
