84: THE AMERICAN MONTHLY [April, 



g, one click, but can be set to any desirable thickness less, by the ad- 

 justable arc, TV. No. 2 gauges to 1-2,000 inch, adjustable like No. 1. 



The King Microtome should not be confounded with " King's Provi- 

 dence Microtome," which is not now in the market ; the principle is 

 the same, but the mechanism is very much simplified and improved. 

 It is made by Charles X. Dalton, of Boston, who did R. B. Tolles' 

 brass work for twenty years, and whose name is a guarantee for the 

 best of workmanship. 



The following table gives thickness of sections by clicks, on No. 1 

 Microtome, omitting fractions of ten-thousandths of an inch : 1 click, 

 1-10,000 inch ; 2 clicks, 1-5,000 inch ; 6 clicks, 1-1,500 inch ; 7 clicks, 

 1-1 ,400 inch ; 8 clicks, 1-1,200 inch ; 9clicks, 1-1,100 inch; ioclicks, 

 1-1,000 inch ; 11 clicks, 1-900 inch ; 12 clicks, 1-800 inch ; 14 clicks, 

 1-700 inch ; 16 clicks, 1-600 inch ; 20 clicks, 1-500 inch ; 25 clicks, 

 1-400 inch ; 33 clicks, 1-300 inch ; 50 clicks, 1-200 inch. 



Zeiss' Catalogue. — Messrs. F. J. Emmerich & Son announce that 

 a new edition of Mr. Zeiss' Catalogue (No. 28) in German has just 

 been received, and will be forwarded to applicants for 10 cents in post- 

 age stamps. It contains many new apparatus and improvements of 

 importance. 



o 



Queen's Catalogue. — James W. Queen & Company, of Philadel- 

 phia, have recently issued a clearance sale catalogue of microscopes and 

 sundries. It comprises (besides other goods in this line) a large num- 

 ber of accessories from their regular list greatly reduced in price. A 

 commendable feature is the fact that Queen & Co. guarantee the condi- 

 tion and proper working of every article. 



New Method for Staining Fibrin and Micro-organisms.* — 



Prof. C. Weigert has devised a modification of Gram's method in which 

 the alcohol and oil of cloves are replaced by anilin oil. The proceed- 

 ure is as follows : — The section (hardening in spirit) is stained with 

 the anilin-gentian violet solution. The staining may be done either on 

 the slide or in a watch-glass. In the latter case the section must be 

 washed with water or with Na Cl solution to remove excess of dye be- 

 fore it is placed on the slide. The section is then nearly dried with 

 bibulous paper and the iodine solution dropped on ; when the latter 

 has acted sufficiently the section is again blotted and then covered with 

 a drop of anilin oil, which must be renewed several times as it quickly 

 takes up the stain. The section becomes gradually transparent and 

 the analin oil is removed with xylol and the section mounted in balsam. 

 If a double stain be desired the additional color must be imparted 

 before the violet. In this method there is no need to remove the celloi- 

 din. By this procedure fungi and. pneumonia cocci are more easily 

 demonstrated than by Gram's method, but its principal recommenda- 

 tion is the sharp stain it imparts to threads of fibrin. Bacteria and fungi 

 appear quite dark, almost black, the fibrin threads a beautiful blue. 



*Fortschr. d. Med , v. (1887) p. 228. 



