Scales for Apothecaries and Assayers

Early North Coast Scientific Instruments

c. 1850 – c. 1950

Richard Paselk, Curator

Scales for Apothecaries and Assayers

Scales and balances are widely used in both science and commerce.

The Pulp Balance is designed as a low capacity, medium sensitivity, scale for weighing the initial sample of crushed ore in the assay process. If 29.17 grams of pulp are weighed out, then the milligrams of purified gold weighed in the assay balance gives the number of Troy ounces of gold in a 2000-pound ton of ore. Troemner offered essentially identical versions of this scale as pulp balances, prescription scales, jewelers scales and laboratory balances.

This Pharmacist’s Box Scale has essentially the same sensitivity and capacity as the pulp balance. It was used at a Eureka Old Town pharmacy located at what is now Many Hands Gallery. Operated as Pacific Pharmacy in the late 19th and early 20th century, and later as Cooper’s Pharmacy (see photo, courtesy of HSU Library), it was known as the place for “ladies of the evening” to buy cosmetics and other essentials a hundred years ago. The pillboxes and bottles are from the Clark Museum collections.

A partial set of Prescription or Apothecary 'Coin' Weights are also included in the display as an example of the weights that would have been used by pharmacists using either balance. The weights are by an unknown maker of early 20th vintage (private collection). In the apothecaries’ weight system there are 20 grains/scruple, 3 scruples/dram, and 8 drams/ounce. A common set goes from ½ grain – 2 drams. The ½ scruple weight is missing from the coin weight set. Two aluminum grain weights (Clark Museum collection) are also displayed.