The calcium content of the serum is a question which has been
much investigated during recent years. Nevertheless we do not
'seem to have arrived, as yet, at a, definite conception of the
variation in amount of circulating calcium in pathological conditions.
This is due to the conflicting evidence put forward by
different observers in so many of these conditions. TLLis investigation
was undertaken as an attempt to decide some of these disputed
questions, and in particular to determine the relationship, if any,
between calcium scry i content and the rheumatoid affections.
Chronic rheumatoid diseases offer an attractive field for
investigation of this subject. In a number of these conditions,
there are marked changes in the cartilaginous and ossified structures
of the body, i.e. in the calcium storehouses. In osteo- arthritis
very definite bony change is observed - both softening of bone and
new formation being present, and in the atrophic group of infective
arthritis osteoporosis is a marked feature. It would appear possible
that with these changes in the stable calcium, some alteration
in the amount ,circulating calcium might be present also Further,
in all previous investigations of calcium in rheumatoids, the group
has been studied as a v hole, and no sub -division has been attempted.
As vastly different conditions are included under this term, it has
been sub- divided into its different sub- groups, and each Studied as
a separate entity.
Inasmuch as a number of females were included in the cases under
investigation, the influence of menstruation upon calcaemia had to
be considered. If marked variations are present during the menstrual
cycle, all 'female subjects would have to be examined at the same period
of the menstrual cycle to obtain comparable results; if otherwise,
it would be immaterial at what stage of the cycle the investigation