586 



PHYSIOLOGICAL CHEMISTRY 



animal 20 c.c. of pasteurized milk daily. Upon the appearance of scurvy, which 

 should occur in from 10 days to 2 weeks, add 5 c.c. of orange juice to the daily 

 ration of each guinea-pig, and note results. The onset of scurvy is evidenced 

 by a variety of symptoms chief of which are the following. The joints become 

 tender so that the animal will wince and cry when it is examined, this tenderness 

 being often accompanied by swelling due to edema or hemorrhage. The animal 

 soon becomes lethargic instead of over excitable, and generally assumes an 

 unnatural posture such as holding up one tender hind leg, "the scurvy position," 



DAYS 



FIG. 174. GROWTH CURVE OF ALBINO RAT SHOWING 



. IMPORTANCE OF WATER-SOLUBLE "B". 

 (Osborne and Mendel: Journal Biological Chemistry, 32, 309, 1917). 



(see Fig. 177) or lying with the side of its face resting on the floor, "face ache 

 position." (See Fig. 178.) A couple of days after orange juice is added to 

 the diet, the animals should show signs of improvement. The length of time 

 elapsing before complete recovery depends upon the individual case. 1 



The Care and Caging of Albino Rats. The type of rat cage illus- 

 trated in Figs. 179 and i So is a suitable one for nutrition experiments. 2 



^or further details concerning scurvy see Hess: ''Scurvy Past and Present," 

 Lippincott, 1920. 



2 This is the type of cage developed and used by Dr. Thomas B. Osborne and Dr. 

 Lafayette B. Mendel in their nutrition investigations. See description of methods and 

 technic by Edna L. Ferry, J. Lab. Clin. Med., 5, 735, 1920. 



