1921] Proceedings of Elisha Mitchell Scientific Society 107 



a contribution of Klein to see in group theory a logical classification 

 of geometry. Classified from the viewpoint of groups of transform- 

 ations, geometry falls into projective geometry, metric geometry, 

 etc. Some investigations require a knowledge of a geometric figure 

 only in a limited region; others require a knowledge of the figure as 

 a whole. We are thus led to a sub-classification: differential and in- 

 tegral geometry. Four kinds of geometry thus arise: the projective 

 differential geometry of Halphen, Wilczynski and Green, the pro- 

 jective integral (known as projective) geometry of Desargues, the 

 metric differential (known as differential) geometry of Gauss, and 

 the metric integral (known as geometry) geometry of Euclid. The 

 developments in geometry to which this paper calls attention are those 

 in the field of projective differential geometry, 



C. S. Mangum — A Review of the Public Health Work in North Carol- 

 ina. 



Progress in health work is indicated by a reduction in death rates. 

 For the whole United States the death rate is 12.9 per thousand of 

 population. In North Carolina it is 12.4. This is lower than the 

 known death rate in any other of the old states from Maine to Texas. 



This record is all the more creditable when one considers the fact 

 that North Carolina's birth rate is the highest of all the states in the 

 Union, and is steadily increasing. 



The State Board of Health, in conjunction with allied associations, 

 has for years conducted a well organized and energetic campaign 

 which has shown most encouraging results in a number of fields. 



In 1914 there were 8,390 cases of typhoid fever and 839 deaths. 



In the last twelve months there have been 2,750 cases with 275 

 deaths. A reduction of two-thirds. 



Within the same period the death rate from diphtheria has been 

 cut in half. In 1914: deaths 525. In 1920: deaths 242. 



The deaths from tuberculosis have decreased from 3,710 in 1914, 

 to 3,005 in 1920. A gain of 705. 



The work of the Board may be classified under three heads: 



(1) Educational. Through the wide distribution of the ''Bulle- 

 tin" and thousands of special pamphlets, public lectures and pubhcity 

 campaigns; using the County as a unit. 



(2) Prophylactic. Supervision of the care of expectant mothers 

 and of infants; Intensive campaigns against preventable diseases, 

 distribution free or at a nominal cost of vaccines and antitoxins, 



