INFLAMMATORY AFFECTIONS 317 
ticle of diseased horn must be carefully removed from both 
sole and frog, a process much more easily, and with far 
greater certainty, secured by the previous thinning of the 
horn. 
‘The removal of diseased horn should always commence 
at the most dependent part of the foot, so that any hemor- 
rhage produced may be below the parts still to be operated 
on, a matter of considerable moment for effective treatment. 
But with due care there will be little hemorrhage, as, 
except in the initial stage, there is no real union between the 
diseased horn and the diseased vascular secreting surface. 
‘ After all apparently diseased horn has been removed by 
the knife, any still remaining should be at once destroyed 
by the actual cautery, by which it can be identified. All 
the diseased secreting surface should be carefully scraped 
with a thin hot iron,* fungoid growths excised and cauter- 
ized, and, indeed, every particle of cankered tissue should, 
if possible, be eradicated. In securing this more reliance 
can be placed on the actual cautery than on any other, 
whether liquid or solid: it is more under control in applica- 
tion, more decisive in effect, and its results can be antici- 
pated with a far greater certainty. Moreover, its aid in 
diagnosis is of immense value ; applied to the thinned horn 
or secreting surface it unmistakably demonstrates the pre- 
sence or absence of canker. Healthy tissue chars black ; 
cankered tissue, on the contrary, bubbles up white under 
the hot iron, and presents an appearance not unlike roasted 
cheese. 
‘Although this test is certain for horn thinned to the 
quick, it is not to be relied upon with thick horn, the out- 
side of which may be practically healthy and char black, 
while its underlying surface may be cankered. With this 
exception the test is an infallible one, as by it the demarca- 
tion between cankered and healthy tissue can be clearly 
traced, and as a result we can with equal confidence radi- 
cally remove * all cankered tissue, and conserve all healthy. 
* The words in italics are alterations in the original article made by 
Mr. Malcolm in a private letter to the author (H. C. R.). 
