TRANSACTIONS OF SECTION PB. 487 
12. Caleiwm: its Properties and Possibilities. 
By Arruur E. Pratt, B.Sc. 
General Properties.—Calcium is a silvery white metal readily oxidised in moist 
air. It is very light (sp. gr. 1-52), fairly malleable, has a high specific heat, and 
is a gocd conductor of electricity. It is about as hard as aluminium, but at 400°C. 
becomes as soft as lead. It is volatile, and can be sublimed zz vacuo between 
700° C, and 800° C., and melts at the latter temperature. It is a very powerful 
reducing agent. 
Calcium Alloys.—The chief effects of alloying calcium with other metals are to 
produce brittleness, crystallisation, and hardness; to promote oxidation and dis- 
integration on expusure to air; to confer the power of decomposing water and 
in other ways increasing the chemical activity. 
~ The author’s experiments confirm Roberts-Austen’s observation that the 
presence of small amounts of metals of high atomic volume will cause deterioration 
of the physical properties of metals of low atomic volume. The atomic volume of 
calcium is high (25:4), and the effect of small amounts on other metals is 
decidedly prejudicial, provided that the metals in question are pure. The experi- 
ments were conducted in a converse manner to Roberts-Austen’s, 7.e., the constant 
was a metal of high atomic volume (calcium) instead of being low (gold). In 
the course of the work the following observations were made: When an alloy 
is made of calcium and some metal which possesses a chemical property in common 
with it, an increased activity in the manifestation of that property is noticed in the 
alloy. This increase appears to be greater than would be obtained by the simple 
admixture of a more active metal, the presence of calcium usually increasing the 
activity of the other metal. In some cases the alloy is more active than either of 
its constituents, 
Further, the chemical properties of calcium appear to be more pronounced in 
an alloy with a metal having an atomic volume closely approaching that of calcium 
than they are in an alloy of the same percentage with a metal having a much 
lower atomic value. The two metals in question should be about equally active 
when unalloyed in the particular property with respect to which they are to be 
compared. 
It is probable that both these principles are general, and not confined to 
calcium, although more extended research on these lines would be desirable. 
Industrial Possibilities—The most promising applications of calcium are as a 
reducing agent and for the refining of metals. In the latter case it acts in three 
distinct ways: (1) By reducing oxides and sulphides; (2) by eliminating dissolved 
gases ; (3) by forming compounds with certain impurities, thus rendering them Jess 
deleterious, All three modes of action are strikingly shown in the case of copper. 
A suitable addition of calcium will remedy ‘dry’ or ‘sulphury’ copper, give a sound 
casting, and give a soft and tough ingot with prohibitive proportions of bismuth or 
antimony, besides restoring ordinary overpoled copper to tough pitch. If excess of 
calcium is present, however, it induces brittleness on its own account. 
With one or two doubtful exceptions, no alloy of calcium has shown any 
promise of commercial utility so far as physical properties are concerned, its only 
likely application in this direction being its hardening property. 
TUESDAY, AUGUST 6. 
Discussion on the Chemistry of Wheat and Flowr, with Special 
Reference to Strength. 
(i) Causes of the Quality Strength in Wheaten Flour. 
By A. E. Houmpuriss. 
The Home-grown Wheat Committee of the National Association of British and 
Trish Millers has for several years been engaged in producing wheats in England 
