22 rnePorr—1890. 
An analogous influence was found to be exerted by those two groups 
of elements upon the permanent magnetisation of steel. 
Captivating as such deductions are, those who have deyoted much 
attention to the practical investigation of iron, steel, and other metals, 
cannot but feel that much caution has to be exercised in drawing broad 
conclusions from the results of such researches as these. Like the in- 
vestigations recently made with the object of ascertaining the condition 
in which carbon exists in steel, and the part played by it in determining 
the modifications in the properties developed in that material by the 
influences of temperature and of work done upon it, they are surrounded 
by formidable difficulties, arising from the practical impossibility of 
altogether eliminating the disturbing influences of minute quantities of 
foreign elementary bodies, co-existing, in the metal operated upon, with 
those whose effects we desire to study. Certain it is, however, that by 
acquiring an accurate acquaintance with the composition of varieties of 
iron and steel exhibiting characteristic properties; by persevering in the 
all-important work of systematic practical examination of the mechanical 
and physical peculiarities developed in iron and steel of known composi- 
tion by their association with one or more of the rarer metals in varied 
proportions, and by the further prosecution of chemical and physical 
research in such directions as those which have already been fruitful of 
most instructive results, such talented labourers as Chernoff, Osmond, 
Roberts-Austen, Barus and Stroudal, Hadfield, Keep, James Riley, Stead, 
Turner, and others, cannot fail to contribute continually to the develop- 
ment of improvemeuts equalling in importance those already attained in 
the production, treatment, and methods of applying cast iron, malleable 
iron, and steel, or alloys equivalent to steel in their qualities. 
The causes of the variations in the physical properties of steel pro- 
duced by the so-called hardening, annealing, and tempering processes 
were for very many years a fruitful subject of experimental inquiry, as 
well as of theoretical speculation with regard to the condition in 
which the carbon is distributed in steel, according to whether the metal _ 
is hardened or annealed, or in an intermediate, tempered state. Recent 
researches have made our knowledge in the latter direction fairly pre- 
cise; as yet, however, we are only on the track of definite information 
respecting the nature and extent of connection between the physical 
peculiarities of steel in those different conditions and the established 
differences in the form and manner in which the carbon is disseminated 
through it. 
The careful systematic study of the modifications developed in certain 
physical properties of iron and steel by gradual changes of temperature 
between fusion of the metal and the normal temperature, has shown 
those modifications to be governed by a constant law, and that at cer- 
tain critical temperatures special phenomena present themselves. This 
important subject, which was so clearly brought before the Association 
