27th Thousand. 



LECTUEE I. 



THE title of this lecture is " Preventable Diseases and their 

 Causes," and I have chosen it to indicate as nearly as possible 

 the nature of the subject I have to speak of. Under this title 

 we include, for the present, only such as come under the head 

 of Zymotics that group of diseases, viz. : which are more 

 directly affected by public measures of prevention, and by 

 the conditions which affect large communities. Many other 

 diseases which are, strictly speaking, preventable, such as 

 arise from noxious trades and unhealthy occupations, are not 

 here included, but will, I trust, at some future time, form the 

 subject of an interesting and useful lecture to you. A prevent- 

 able disease may be described as one which arises or spreads in 

 consequence of the wilful, careless, or ignorant violation of those 

 laws, the proper observance of which we know to be necessary to 

 insure the preservation of health, and avert the spread of disease.* 

 Those diseases a very numerous group which result from per- 

 sonal vices or from depraved habits of the community, are 

 beyond the immediate control of public measures. 



The chief of the zymotic diseases are : smallpox ; typhus 

 fever ; typhoid (or enteric fever) ; scarlet fever (or scarlatina) ; 

 dihptheria ; measles ; and Asiatic cholera. We will consider them 



* Grimshaw. 



