Explanation of Allan's Saccharometer, Appointed by Act of Parliament for the Use of Distillers and Brewers

Edinburgh, Scotland: J. Ruthven & Son, 1823. First Edition. Pamphlet. Very good. A scarce instruction manual for a saccharometer, a scientific instrument used to measure the sugar content of a liquid, typically used in brewing. In addition to the instructions, this pamphlet includes two tables for calibrating the device at various temperatures and for interpreting the results.

In the early 19th century, Dr. Thomson invented an improved method of determining sugar content during the brewing process. He licenced the invention to the instrument maker Alexander Allan. It was a great improvement over previous devices, in part because it included a thermometer and could be used at a wide range of temperatures. By measuring the sugar content of the wort (the liquid produced from grain that is then fermented to make beer), the alcohol content of the finished product can be estimated with good accuracy.

Beginning in 1805, Scottish Excise used Allan's Saccharometer as the basis for collecting taxes on all beer and spirits in Scotland. Despite the device's widespread use, this instruction book is uncommon, with holdings located only at the National Libraries of Scotland and Ireland.

10 pages plus two double-page tables. 4-1/2 by 7-1/4 inches. First edition (no earlier edition is noted in OCLC or COPAC; later editions are noted in 1834, 1840, and 1845). A very good copy in the original thin, unprinted, paper-covered boards. With the ownership signature of Alexander Struthers, dated 1825, with his notes on several pages converting English measurements to metric. Struthers seems to have been a brewer in Glasgow, at various times on his own and in partnership with his brother Robert.