THE MICROSCOPE. 67 



The year 1630 brings to our minds the name of one to whom 

 more than all others we are indebted for valuable discoveries in 

 optics. This was the j^ear when Descartes first gave the scientific 

 world the great law, " The amount of refraction is proportional to 

 the line of the angle of incidence." 



It was about this time in the Christian era that individuals 

 finding themselves unequal to compete successfully with the many 

 inquiries to which scientific pursuits led them, the philosophers of 

 Italy, under the patronage of Leophold, Grand Duke of Tuscany, 

 formed themselves into the first scientific society on record. This 

 academy was called Del Ciniciito. Three years later (1660) Charles 

 II. of England incorporated a philosophical society at Oxford. In 

 1666, the Royal Academj'' at Paris was established. These latter 

 two societies are still in existence and flourishing. The Del Cimento 

 lived but a decade. Though I have no statement of proceedings 

 of these academies it is natural to suppose that during a time when 

 the microscope was such novelty in science circles, that it formed a 

 leading topic for discussion and a center of attraction for investiga- 

 tion at these meetings. A copy of the minutes of their meetings 

 in those olden times when they had but the crudest knowledge and 

 materials to aid them, I am sure would cause a blush of shame on 

 the faces of members of our modern societies. Then they worked 

 for results, each and every member; now, the mass of the member- 

 ship is composed of drones or exhibitors of the result of other men's 

 labors. Cannot we be inoculated with a little of the old time 

 energy? 



In 1668, Mr. Oldenburg, Secretary, of the Royal Society, read 

 at their August meeting an account of a microscope as made by an 

 Italian, Eustachio Divini. As described (Adams' Essays) the in- 

 strument consisted of an object glass, middle glass or amplifier 

 (which is the firsh account of this accessory I can find) and an eye- 

 piece, made of two plano-convex lenses which touched each other 

 by convex surfaces. By these combinations "the field is made 

 larger, the extremities less curved and the magnifying power 

 greater." The tube of the microscope was as large as a man's leg 

 (this, generally speaking, is rather indefinite, but inasmuch as the 

 describer is an Englishman, we conclude the calibre of the tube was 

 not capillary) and the eye-glasses as broad as the palm of a hand. 

 It had three draw tubes, giving four different lengths and conse- 



