INFLAMMATION. 395 



Frony these experiments it follows that we are able to produce 

 artificially in carnivorous animals, by continued administration of 

 lactic acid, first, rachitis, and afterward osteomalacia ; while in 

 herbivora the same agent produces osteomalacia without a prelimi- 

 nary rachitic stage. 



Thus, the identity of these forms of disease is demonstrated, 

 and the differences in their course depend mainly upon the differ- 

 ence in the age of the animals in which the solution of the lime- 

 salts is produced. 



In October, 1873, I exhibited to the Society of Physicians, in 

 Vienna, a female foetus of seven months, which had died immedi- 

 ately after birth. The mother of this foetus had been employed 

 by me for months to feed the animals with lactic acid. In this 

 foetus the symptoms of congenital rachitis were in the highest 

 degree marked, to such an extent that the skull-bones were 

 entirely absent, the cartilages of the ribs and the extremities 

 showed only scanty depositions of lime-salts, but numerous 

 breaches in the continuity; and throughout the body of the other- 

 wise well-developed foetus there could be found no trace of bone- 

 tissue. 



Feeding with lactic acid was repeated by E. Heiss,* on a dog 

 one year and six months old, with only negative result. The age 

 of dogs and cats in which rachitis can be induced is between the 

 first and six months of life at the period, therefore, when the 

 skeleton is developing from the cartilage and the periosteum. 

 After this stage of development is passed, the symptoms of osteo- 

 malacia will be produced, and with greater certainty, toward the 

 end of the first year of the animal's life. The experiments of 

 Heiss rest on mistaken grounds. Age is an essential factor in 

 the production of either of these diseases in human beings. 

 Rickets occurs only in children between the first and the fifth 

 years of life, this corresponding with the age of the above-named 

 animals. Osteomalacia is exclusively a disease of adults. 



Rachitis (Rickets}. This disease of early childhood in its clin- 

 ical features has been well known for over two centuries. 



Whistler t was the first to describe it, and from the title of his book the 

 name of " English disease "was adopted by the German physicians. Next 

 followed G. Glisson,t who made use of the name " rhachitis." 



Simon, according to Marchand and Lehman, found lactic acid in the urine 



* "Zeitschr. f. Biologic," Bd. xii. 



t " De Morbo Puerorum Auglorum," 1645. Rare book. 



t "Tractatus de Rhaehitide," 1659. 



Lehrbnch d. Med. Chemie., 1842. Bd. ii., p. 203. 



