SCIENTIFIC SEMMAET. 
99 
all the pores 'within a very limited space in the centre of the steel block. 
This fact is of the utmost importance in the manufacture of heavy steel 
ordnance, which is intended to bear the strain of very great charges, as in 
that case it is just the central part of the barrel which is bored out and the 
perfectly sound part of it left to form the wall of the gun. Thus the 
pressure of from 6 to 9 tons on the square inch will be sufficient to com- 
press a red-hot steel ingot before its solidification, and give it an even 
structure throughout the whole mass, while the impact even of a very 
heavy steam-hammer, like Krupp’s 50-ton hammer, is principally spent on 
the outer part of the block, and the result will be the absorption of the 
power before it reaches the centre, and the exterior of the mass will be 
elongated and cause the tearing asunder of the central part. Only very 
heavy hammers or rams will efiectually overcome the vis inerticv which a 
very heavy casting opposes to them. 
MEDICAL SCIENCE. 
A General JEiiropean Tharmacopceia is likely to be formed eventually. At 
all events already a considerable number of distinguished medical men are 
strongly in favour of it. Dr. Thudichum read a paper on the subject at the 
meeting of the Pharmaceutical Society on the evening of November 16th. 
Attempts have been made, according to Dr. Thudichum, for the past 200 
years, but alas ! unsuccessfully. 
The Value of Chloralum as a disinfectant has been tremendously over- 
rated. This is not, as many represent, a quite recently discovered substance, 
but a very old one, and one too, whose disinfecting qualities were known. 
Eegarding these properties a recent writer. Professor A. Fleck, states that 
both the disinfecting and purifying power of chloralum stand below those of 
alum, or sulphate of alumina and copperas (protosulphate of iron), which 
further recommend themselves by their much greater cheapness. To snm 
up the argument concerning the value and composition of the preparation of 
chloralum : 1. The preparations of chloralum have nothing in common with 
the similarly-sounding chloral hydrate, and are, in point of fact, mixtures of 
chloride of aluminium. 2. The preparations of chloralum contain chlorine 
combinations of lead, copper, and arsenic, which renders their employment 
not free from danger, and which would render their employment, as a medi- 
cine or as an astringent for open or suppurating wounds, dangerous. 3. The 
price of the preparations of chloralum bears no relation either to their nature 
or their effect. Considering that the liquid chloralum yields a clear profit 
of at least 700 per cent., and the wadding 400 per cent., the limits of trading 
may be considered as overstepped. 4. The result of these experiments is 
that chloralum and the preparations made from the same must be classed 
among the worthless arcana, and in the interests of the public health, as well 
as in the material interests of the public, a most decided warning must be 
given against the purchase of the same. 
Effects of Substances which alter the Blood-corpuscles. — M. Ritter, of Stras- 
burg, gives the following resume of the results of his researches on this sub- 
