64 THE AMERICAN MONTHLY [Feb. 



Now the use of a hand lens enables one to bring- an object 

 under examination much closer to the eye than is normally 

 possible, for the outer surface of the lens represents that 

 of the eye for the time being-. As a result the object ap- 

 pears much larg-er, and more structural detail is revealed 

 than when the object is viewed by the unassisted eye. 

 Similarly, the compound microscope still further lessens 

 the distance between the object and the eye, the surface 

 of which is now represented by the front of the objective, 

 and to speak of the imag-e of an object as being- enormously 

 mag-nified under the microscope is simply another way of 

 expressing- the fact that the object has virtually 'been 

 broug-ht into such close proximity to the org-an of sig-ht as 

 is normally impossible. Examination of an object by the 

 aid of the microscope, therefore, must be reg-arded as a mere 

 extension of the limits within which the normal human eye 

 is capable of clearly disting-uishing-thedetailsof objects. As 

 spectacles help the partially blind to see, so the microscope 

 enables those with perfect eyes to see more than is possi- 

 ble without such aid, 'and the natural conclusion is that 

 pharmacists and others whose skill is partly dependent 

 upon the accurate impressions they form of the appearance 

 of objects, should be adepts in the use of an instrument 

 that can so increase their natural powers. — Pharmaceuti- 

 cal Journal. 



MICROSCOPICAL MANrPULATION. 



Preservation of Microscopic Specimens. — Dr. Jores de- 

 scribes a method, which he has tested for a year and a 

 half of preserving- organs and tissues so that they retain 

 the color they had when fresh. He finds that five to ten 

 parts of a fifty per cent solution of formalin alone causes 

 the org-ans to assume a tint which varies considerably from 

 the natural color. But instead of using- water to dilute the 

 common formalin solution, he uses one part common salt, 

 two parts of Mag-nesium sulphate, two parts sodium sul- 

 phate in one hundred parts of water. This preserves the 

 color of the blood. 



