METABOLISM IN DISEASES OF BONES AND JOINTS 771 



of osteomalacia following osteotomy in which the flux of calcium was 

 started by the need of the repairing bone. In one of these cases the loss 

 of calcium finally ran up to 9.0 grams a day an enormous amount. 

 Thieme cites two cases in which the osteomalacia was the result of 

 the flux to repair a broken bone. And in the discussion of Thieme's 

 paper, Liniger of Bonn cited another similar case. 



There are many analogies for this process of "overproduction." The 

 best example is probably that of the continual production of free receptors 

 which, according to the theory of Ehrlich, explain^ acquired immunity 

 in such cases as diphtheria and smallpox. Indeed, Weigert has pointed 

 out that overproduction is characteristic of all tissue repair. Harris 

 has written a book on the property which he calls "functional inertia," 

 and has pointed out that the property is as fundamental an attribute of 

 living matter as irritability itself. He defines functional inertia as "that 

 property of protoplasm whereby living matter contrives to remain in a 

 functional status quo ante, notwithstanding that it has received a stimulus, 

 or, having responded to a stimulus, it contrives to exhibit its functional 

 activity for a certain time after the stimulus as a form of energy has 

 ceased." The condition may be compared with a heavy door, which, when 

 at rest, requires a certain time to get into full swing after it has been 

 pushed, and, when moving, takes time to stop if held. Of examples of 

 latent period in starting activity, there is the latent period of muscular 

 contraction, that, occurring after glands are stimulated through their 

 nerves, and before they begin to secrete, and that, occurring before the 

 heart beat begins to accelerate its rate when the augmentor or accelerator 

 nerves are stimulated. Of examples of continued activity may be 

 mentioned the continuation of accelerated heart action for a time after 

 stimulation of the augmentor nervous apparatus has ceased. It is not 

 impossible that another example of such overproduction or functional 

 inertia is the change in the metabolism brought about by morphinism, 

 which enables the body to destroy increasing amounts of morphin, but 

 which continues and has a damaging effect on the body itself, if the drug 

 is suddenly withdrawn. Overproduction is probably another example of 

 the factors of safety with which, as Meltzer has pointed out, the body 

 is so well endowed. 



The occurrence of attacks of osteomalacia, earlier and earlier, in 

 succeeding pregnancies, and the increasing severity of subsequent attacks, 

 make one think of the more severe and rapid production of symptoms 

 of certain diseases ; e. g., serum disease and others after a previous inocula- 

 tion a kind of allergy (von Pirquet(&)), or, to put it still more broadly, 

 "a cell stimulated to perform a certain act not only continues to perform 

 that act for some little time after the stimulus has ceased, but, what is 

 more, on a second occasion a slighter stimulus will induce the like series" 

 (Adami). 



