On Spontaneous Inflammations . 101 
times more heavy, thick, and unctuous, than that kind of 
painter’s black which the Germans call kien-rahm . The 
former is gathered at Ockia, near Bt. Petersburgh, at 
Mosco, at Archangel, and other places, in little wooden 
huts, from resinous fir-wood, and the unctuous bark of 
birch, by means of an apparatus uncommonly simple, 
consisting of pots without bottoms set one upon the other, 
and is sold very cheap. The famous fine German Men- 
rahm is called in Russia Holland’s black . In what fol- 
lows, when I speak of raw oil, it is to be understood of 
!mseed-oil or hemp-oil ; but most commonly the latter. 
The varnish is made of five pounds of hemp-oil boiled 
with two ounces and a half of minium. For wrapping 
up the composition, Mr. Georgi made use of coarse hemp- 
linen, and always single, never double. The impregna- * 
tions and commixtures were made in a large wooden 
bowl, in which they stood open till they were wrapt up 
in linen. 
That I may not be too prolix, I will select and com- 
municate only such of the experiments as were most re- 
markable, and succeeded best. 
Three pounds of Russian fir-black were slowly im- 
pregnated with five pounds of hemp-oil-varnish; and, 
when the mixture had stood open five hours, it w as bound 
up in linen. Ry this process it became clotted ; but 
some of the black remained dry. When the bundle had 
lain sixteen hours in a chest, it was observed to emit a 
very nauseous, and rather putrid, smell, not quite unlike 
that of boiling oil. Some parts of it became warm, and 
steamed much ; this steam was watery, and by no means 
inflammable. Eighteen hours after the mixture was wrapt 
up, one place became brown, emitted smoke, and directly 
afterwards glowing fire appeared. The same thing hap- 
pened in a second and a third place ; though other places 
were scarcely warm. The fire crept slowly around, and 
