282 



ETIOLOGY AND PATHOLOGY OF RICKETS. [BOOK I. 



of the salts of fully formed bone and further serious changes in the 

 decalcified framework. 



In rickets the bones become specifically lighter than in health ; 

 the unossified cartilage contains an increased proportion of water; the 

 long bones contain an increased quantity of fatty matter. The 

 amount of fat is, however, much less in the bones of rachitis than in 

 those affected with osteomalacia. It has been found by Lehmann 

 and Marchand that occasionally in rickets the bones do not yield a 

 normal gelatin when boiled. 



COMPOSITION OF BONE IN RACHITIS 1 . 



Etiology and Very different views have been advanced on the 



Pathology of etiology and pathology of rickets. Petit 2 first sug- 

 Rickets. gested that the disease is caused by the too early 



weaning of infants ; since his time others, with no less reason, have 

 maintained that too prolonged lactation often acts as a predisposing 

 cause, the impoverished milk being incapable of supplying the grow- 

 ing infant with all the materials which its organism requires. 



Whilst some have considered that rickets is induced by an 

 improperly adjusted diet, in which the different groups of food con- 

 stituents are not in their proper proportions, a majority of writers 

 have advocated the view that the disease specially depends upon a 

 deficiency in the lime salts of the food, or in a deficient absorption 

 of lime salts. All these views have been supported by experimental 

 researches which have led to diametrically opposite conclusions ; 

 certain experimenters having, for instance, succeeded in inducing 

 rickets by feeding young growing animals upon meat instead of milk 3 , 



1 Extracted from v. Gorup-Besanez, Lehrbuch d. phys. Cliemie, p. 635. 



2 Petit, Traite des maladies des os, 1741. 



3 T. Guerin, These de Paris, 1859, p. 24. Quoted, at secondhand, by Leon Tripier, 

 Dictionnaire ency elope dique des sciences me'dicales, Troisieme eerie (Paris, 1874). 

 Article " Bachitisme." 



