DR. DRAPER'S LECTURE ON EVOLUTION. i 75 



higher and less in the lower notes, the muscles of the larynx really 

 become the determining forces of the ability to sing, and a great deal 

 depends upon securing for them the necessary practice, as for instance 

 for the execution of rapid successions of tones. And herein lies the 

 difference in the voices of singers, the purity of the tone depending 

 upon the accuracy with which they put the vocal cords upon the 

 stretch, while in those whose tones are impure and faulty, the difficulty 

 lies in their inability to give the requisite tension, and of course the 

 muscles take part in the shortcoming. A correct idea of the sound, 

 height, and depth, of the tone which the singer intends to communi- 

 cate, enables him to strike the correct tension as by intuition, and 

 carries him along its continuance, and through its purity of modula- 

 tion, until it has ceased. 



DR. DRAPER'S LECTURE ON EVOLUTION. 1 



ITS ORIGIN, PROGRESS, AND CONSEQUENCES. 



WHEN, in the beginning of the present year, I received a request 

 to deliver before this Institute a lecture on the subject of Evo- 

 lution, I was at first disposed to excuse myself. Holding religious 

 views which, perhaps, in many respects are not in accordance with 

 those that have commended themselves to you, I was reluctant to 

 present for your consideration a topic which, though it is in truth 

 purely scientific, is yet connected with some of the most important 

 and imposing theological dogmas. Whatever conclusion is eventu- 

 ally reached respecting it will have an influence on them. But there 

 was that liberality of sentiment in your letter that earnest desire for 

 the ascertainment of truth that I cast aside these hesitations, and 

 am now here in obedience to your wishes. 



Not that I can do justice in an hour to so great a subject, the 

 literature of which ranges through many centuries. It is no new- 

 fangled romance, as some would have us believe. It comes to us 

 from a venerable antiquity. The theorems it expresses, and indeed 

 on which it is based, have long ago been clearly known. 



Considering the shortness of the time allotted me, the vast ex- 

 tent of the subject, the special character of this audience, and the 

 nature of your request, I perceive that it is not an elaborate exposi- 

 tion of the evidence in favor of the theory of evolution that I must 



1 The ministers of the Unitarian Church have recently held a meeting of their Insti- 

 tute at Springfield, Massachusetts. They had requested Dr. John W. Draper to deliver 

 before them a lecture on the subject of Evolution. This accordingly was done on Thurs- 

 day, October 11th. Some passages omitted in the lecture for want of time are here in- 

 troduced. 



