IDENTITY OF PLEURO-PNEUMONIA AND RUBEOLA. 639 
in this paper. However, it is of all known substances found 
in nature that which contains the most phosphate of lime, 
the per-centage of which in the commercial specimens 
averages from 85 to 87 per cent., and in absolutely pure 
specimens as much as 92. 
The remaining phosphates used in agriculture are bones, 
bone-ash, and animal charcoal; the two latter are merely 
burnt bone. Bones contain the peculiar phosphate known 
as “ bone-earth,” equivalent to about 56 per cent, of ordinary 
tribasic phosphate of lime. When ground, they often become 
mixed with silica and other impurities. Enormous cargoes 
of ox-bone, either sun-dried or in the shape of bone-ash, are 
imported from South America into England. 
Bone-ash is bone burnt in contact with the air until its 
organic matter is destroyed; it yields a quantity of bone 
phosphate equivalent to 70 or 90 per cent, of ordinary phos¬ 
phate of lime, according to its degree of purity. When burnt 
without contact of air , animal charcoal is obtained; this is used 
to clarify sugar, juice, &c., and when spent is burnt over 
again. After being thus burnt twice or thrice, it becomes 
comparatively useless to the sugar-refiners, and is sold to 
manufacturers of superphosphate. According to a number of 
analyses made of this substance in my laboratory, it may be 
said to average from 70 to 80 per cent, of phosphate of lime. 
Such, then, are the substances which furnish our agricul¬ 
turists, our lucifer-match manufacturers, our colour-makers, 
&c., with their supplies of phosphate of lime. It is needless, 
perhaps, to add that agriculture absorbs by far the greatest 
portion of this phosphate, and we may be thankful that there 
exists so plentiful a supply of it. In a future paper I will 
consider our present sources of ammonia. 
ON THE IDENTITY OE PLEURO-PNEUMONIA AND RUBEOLA. 
By W. Thomson, M.R.C.S., &c. 
(Read before the Medical Society of Victoria .) 
(Continued from p. 547.) 
But we never speak of the group by the terms applicable to 
or descriptive of anything connected with their secondary, yet 
not less exact, states, not of any of them individually in this 
way, unless it be of typhoid fever, although even in that case 
we never say enteritic ulceration to signify typhoid or pytho- 
genic fever. It belongs also to these fevers, as a character- 
