Vol. 6, 1920 PATHOLOGY: UNDERHILL, HONEIJ AND BOGERT 81 
The suggestion that plenty of calcium and magnesium be supplied in 
the food in leprosy as a therapeutic measure is at least worthy of trial. 
Multiple Exostosis. — From a consideration of the study of multiple 
exostosis it may be concluded that in the stabilized stage of this disease 
calcium exchange differs little from that of a normal individual whether 
the abnormal subject is maintained upon a calcium-poor or a calcium- 
rich diet. 
In the progressive stage of the disease calcium metabolism is markedly 
different from the normal in that calcium is lost from the body in rela- 
tively large amounts when the subject is maintained upon a calcium-poor 
diet. This excessive elimination of calcium is excreted by both the urine 
and feces in a normal ratio. When placed on a calcium-rich diet cal- 
cium is retained in the body to an extent not widely deviating from that 
obtaining in normal subjects. A resumption to a calcium-poor diet again 
induces excessive calcium elimination. 
In the stabilized stage of multiple exostosis magnesium excretion is 
two or three times as great as the intake whether the subject is main- 
tained upon a diet poor or rich in magnesium. 
In the progressive stage of the disease the general type of magnesium 
excretion resembles that of the stabilized stage but the degree of elimination 
is not so marked. 
Magnesium added to the diet in the stabilized stage results in the prompt 
excretion of the same. The same test applied to the progressive stage gives 
evidence of the retention of some magnesium. The degree of retention, 
however, is much less than that shown by normal individuals. 
Absorption of both calcium and magnesium in multiple exostosis is not 
inferior to that of normal subjects. 
The facts enumerated suggest that in the early stages of this prolifera- 
tive type of bone disease under discussion a check may perhaps be given 
to the progress of the disease by proper dietary procedure — restriction of 
calcium and magnesium intake. 
Summary. — Clinically, in leprosy there is evidence of loss of bone salts; 
experimentally, the leprous organism gives evidence of a marked tendency 
to retain or conserve bone salts, more especially calcium. 
Clinically, in multiple exostosis it may be inferred that bone salts are 
added to the body; experimentally, in the progressive stage of the disease 
the organism attempts to rid itself of bone salts, particularly calcium. 
In the stabilized stage the organism throws out excessive quantities of 
magnesium. 
These facts suggest possible beneficial results in treatment by the 
institution of proper dietary procedures. 
