Determination of Gaiactan. 
tty 
K. Miyake. 
The presence of gaiactan (or substances containing a galactose group in 
the molecule) in natural products has been shown, in recent years, by numer- 
ous investigators. 
Quantitative determination of gaiactan has therefore been deemed desir- 
able and the following method 0 , the underlying principle of which had been 
worked out by To liens and his associates,- 5 was provisionally adopted by 
the association of the official agricultural chemists, U. S. A., for its determi- 
nation in foods and feeding stuffs. 
“Extract a convenient quantity of the substance, representing from 2.5 
to 3.0 grams of the dry material, on a hardened filter with five successive 
portions of 10 cc. of ether, place the extracted residue in a beaker about 5.5 
cm. in diameter and 7 cm. deep, together with 60 cc. of nitric acid of 1.15 
specific gravity, and evaporate the solution to exactly one-third its volume 
in a water bath at a temperature of 94°to 96°C. After standing twenty- 
four hours, add 10 cc. of water to the precipitate, and allow it to stand 
1) TJ. S. Department of Agriculture, Bureau of Chemistry-Bulletin No. 107 (Revised). 
Official and Provisional Methods of Analysis, P. 55. 
2) B. To liens- Kurzes Handbuch der Kohlenhydrate, II, Breslau, 1895, P. 52. 
