TSE CHAIN OF SPECIES. 313 



of each other to " solidify," reject the instrument ; but, if they meet 

 well when farther apart, the fault was in the pictures. 



A friend complained to me that the stereoscope she had bought, 

 on my recommendation, was worthless. I had taken it on faith, sup- 

 posing that all "Holmes" instruments must be good; but a short ex- 

 amination showed that the glasses were rather flat, and were placed 

 so near together that the rays came to the eyes through the central 

 part of the lens, and of course without refraction, and hence the eyes 

 were not deceived. By whittling out the frame, and moving each 

 glass outward about three-eighths of an inch, a good instrument was 

 made. 



If a view does not "stand out well" when seen in a good instru- 

 ment, examine each picture by itself, and try to find a well-defined 

 object, as a post or tree, in the foreground, and note its relations to 

 some other object in the distance. If the two objects have the same 

 relative position in both, the pictures are duplicates, and worthless. 



If the distant object is to the right of the near one, they should 

 appear farther apart in the right-hand picture, and vice versa ; if not 

 so, the pictures are mounted on the wrong ends of the card, and are 

 worthless, or worse. 



THE CHAIlSr OF SPECIES.^ 



By Hon. LAWRENCE JOHNSON. 

 Part I. — Science and JReligion. 



THE subject selected for this evening's entertainment — the evolu- 

 tion and metamorphoses of organic forms, from the genesis of 

 life up to man — with all its difficulties, might, in skillful hands, be 

 made amusing ; but, let us rather hope for the earnestness, however 

 dull, which will instruct, instead of the light talent which can while 

 away an idle hour. It is a subject which has escaped from the pin- 

 fold of the learned, and become public property, at least in part ; and 

 we see it engaging the attention of news-mongers, writers of squibs, 

 and makers of woodcuts, as well as the graver interests of literary 

 circles, and the thunders of the pulpit. 



And here let us pause a little to place ourselves right with our- 

 selves, and right with the rest of the world. 



As it is proposed to view this matter, there is not one particle of 

 religious interest in it, any more than there would be in a lecture on 

 geology, chemistry, or any other pure science ; and, in the name of 

 truth, system, and logic, I must protest against the unscientific, un- 



1 An address, delivered before the Franklin Society of Mobile, June 4, 1872, by Hon. 

 Lawrence Johnson, of Holly Springs, Mississippi. 



