and Laboratory MethodSc 2643 



render the microscope entirely useless in showing the fact which is sought to be 

 shown. It is an almost universal fallacy that the greater the magnification the 

 better, the fact not being known or considered that the field of view is diminished 

 in proportion to the degree of magnification. For examination of crossed lines, 

 traces of pencil marks, line edges, paper fiber, retouching, and ink condition, 

 quite high magnification may be useful, but for examination of writing as writing 

 a magnification of from ten to fifty diameters gives the best results. 



Fig. 8. — Check punch perforations filled in and larger amount punched out of same field. 

 S24S changed to $2400. Transmitted light view under magnification showing transparent 

 rings around filled in portions. 



Objections to the use of the microscope in court are based upon the some- 

 what natural but erroneous idea that what exists that is significant can be seen 

 by unaided vision. Ordinary spectacles are simply lenses placed between the 

 eye and the object looked at, by which means sight is corrected and improved, 

 and the most elaborate and complicated microscope is nothing more than an 

 extension of this principle. To be consistent, one who objects to the use of the 

 microscope should also insist that judge and jury should be compelled to remove 

 spectacles before examining a document that is questioned in a court of law. 

 Rochester, N. Y. ALBERT S. OsHORN. 



An Absolute Alcohol Still. 



In 1895, while working in the Anatomical Laboratory of the Johns Hopkins 

 University, it occurred to me that the home manufacture of absolute alcohol 

 would be more economical and satisfactory than buying it in small quantities. 

 With permission from Dr. F. P. Mall, a small still was made which for a time 

 gave satisfactory results. This apparatus consisted of an ordinary tin can and 

 an inverted Liebig's condenser for the first portion of the work. When ready for 

 distillation the condenser was changed to the inclined position and the alcohol 

 was caught in an ordinary receiver. While this apparatus gave satisfactory 

 results, it required more care and knowledge for its operation than can ordinarily 

 be placed in an average janitor, already busy with numberless small chores. 

 Since then, an absolute alcohol still has been constructed by Dr. Mall, which 

 requires practically no care or thought on the part of the operator, yields an 



