144 
ON THE PROCESS FOR PREPARING JAMES’S POWDER. 
spersed with a deep yellow-coloured portion. This fact pointed to the conclu¬ 
sion that the ladle was too small for that quantity of n aterials, that due raking 
during the heating was impeded, and that the desulphuration was accordingly 
imperfect. A hemispherical ladle capable of holding a gallon being procured, a 
charge of ten ounces of each was placed on the fire and continually raked for 
several hours, at first without any intermission, and at length with short intervals 
of rest until the proper colour was attained. This matter, being finely pow¬ 
dered, was introduced into a proportionately large skittle-pot and exposed to a 
well-built coal fire in a common grate, and kept red-hot for three hours. When 
cold the top portion proved to be a thin cake of dark-coloured matter ; under 
that'was a small quantity of yellow portion ; and the remainder was very nearly 
snow-white. . „ . . .. , . ,, , 
On trying so large a charge as sixteen ounces of each ingredient in the large 
ladle it proved to be unmanageable : the carbon at an early period ignitecl; the 
mass softened, collected into dark-coloured lumps, which could not be raked not¬ 
withstanding much effort. Finding it impracticable, I took out the charge when 
cold and being powdered, it was returned into the ladle in four different por¬ 
tions each of which was separately raked while heating, until the proper colour 
appeared to be attained. The whole of the powder being charged into a very 
laro-e skittle-pot, was heated in a well built and well-supplied fire for several 
hours. The powder, when cold, was found to be yellow throughout; for the 
proper proportion between the quantity of matter and the containing iron lad e 
had not been observed, the necessity of which was thus amply proved. It is a 
certain fact that a large quantity in a small ladle will never afford a white 
By reversing the conditions of the process, that isby acting with due care 
on a small quantity of materials in a very large ladle, we are pretty sure of 
bringing the charge safely through its first stage of danger. Thus when tour 
ounces of hartshorn-shavings and the same weight of sulphuret of antimony 
were well raked in a ladle of the capacity of a gallon, until the requisite colour 
was attained, and then heated in the skittle-pot for an hour or more in the 
usual manner, the powder almost always turned out white, generally snow- 
white, but sometimes with the cream-coloured tiuge noticed by Pearson. Under 
the condition of small charges in a very large ladle, the snow-white colour was 
sometimes produced by a very hot fire in fifteen minutes after the skittle-pot 
had become red-hot, but with a fire not so hot, a much longer time was 
After^following up these experiments for some time, I found that much 
trouble and anxious watching would be saved by raking the bone- shavings, 
without the sulphuret of antimony, until the ammomacal fumes, the sulphur, 
aud the extremely fetid gases had been expelled ; and making proper allowance 
in subsequently apportioning the antimony. . , ... 
Adopting this method, six ounces of calcined hartshorn-shavings mixed with 
four ounces of sulphuret of antimony, were raked over a graduated fire, in my 
largest ladle, until the powder had assumed the usual yellowish-grey hue. It 
was then transferred to a small skittle-pot, which, being placed on a stand m a 
large fire-grate, coals were built round and over it, aud a cover applied, the 
skittle-pot was kept red-hot for six hours. When cold, it was cautiously 
examined. IS T o part of the partially cohering powder was white; it was almost 
all dark grey, but much darker towards the top; the portion at the very top 
was full of particles of metallic antimony, and even small masses of it which 
had assumed a somewhat rounded form. The dark grey colour of the whole 
mass seemed to be caused by the intermixture of thousands of minute shining 
particles of the metal with the phosphate of lime. Round the mouth ot the 
skittle-pot and on its cover was a small accumulation of white powder, some ol 
