Always the Unusual

Copyright Duncan Robert Antiques 2007.  E&O E.

Marbel Blood-Cell Calculator

 

Percentage calculator for differential blood films. Adding machine for 

erythrocytes, leukocytes, blood platelets. Patented June 6, 1922. Black enamel housing. Length 10 3/4 inches. 8 nickel brass keys allowing for  simultaneous counting of individual types and giving a total  for all cells. Nickel  worn on 2  keys. Label of Toronto General Hospital.

 

Fine working order.