2 TECHNICAL BULLETIN 134, U. S. DETT. OP AGIUCULTURE 
SOURCE AND STRUCTURE OF SQUILL 
Squill, Urginea maritima (L) Baker, also called U. scilla Steinheil, 
IS a perennial plant growing wild on the coast of southern Italy, 
Sicily, and Sardinia, and elsewhere along the Mediterranean Sea. 
The bulbs produced are pear shaped, usually from 3 to 6 inches in 
diameter and from 300 to 2,000 grams in weight (pi. 1), and are 
composed of closely overlapping fleshy scales. The outer scales are 
dry, brittle, and reddish brown; the inner scales vary from light 
yellowish white to deep cherry or mahogany; and the central ones 
(core) are usually white. 
There are two commercial varieties of squill — white squill, which 
is marketed as dry, white scales and is the product official in various 
pharmacopoeias, and red squill, which until recently was obtainable 
only in the fresh state. Both the viscous, mucilaginous juice and 
the dry scales of each variety are irritatmg to the skin. This sting- 
ing effect upon the sldn, as well as the acrid prickly taste, is commonly 
attributed to calcium-oxalate raphides. White squill is used in human 
medicine as a heart tonic, em.etic, diuretic, and nauseant expectorant. 
Various European investigators have recommended red squill as a 
rat poison. 
Microscopic examination of squill was made by George L. Keenan, 
of the Food, Drug, and Insecticide Administration, who states: 
A microscopic examination of red-squill powder shows that the anatomical 
structure is similar to that of white squill. The powdered bulb of both varieties 
consists of fragments of parenchyma cells, spiral vessels, and long raphides of 
calcium oxalate, some of which are surrounded by dried masses of transparent 
refractive material, the mucilage sheath. The longest acicular crystals are ap- 
proximately 1 millimeter long. Short raphides are present also. The greatest 
diagnostic difference is the presence of pigment cells in the red-squill scales and 
their absence in the white. The red pigment cells are numerous in the scales 
of the red squill and are readily found in the powdered material. 
To facilitate its identification, the red squill was reduced to a fine powder 
and examined microscopically in a drop of menstruum consisting of an acidified 
chloral-hydrate-glycerol solution (made by dissolving 45 grams of crystals of 
chloral hydrate in 25 cubic centimeters of dilute hydrochloric acid (1:8) and 
10 cubic centimeters of glycerol). The slide was not warmed. The red coloring 
matter gradually diffused out of the cells, giving the pigment masses a reddish 
appearance. Long raphides of calcium oxalate were found in the dried mucilag- 
inous material, many in close proximity to the red masses. 
When a powdered dry bait containing 5 per cent of red squill was examined 
according to the method just described, the pigment cells were readily found. 
RESULTS OF PREVIOUS INVESTIGATIONS 
CHEMICAL 
An exhaustive review of the chemical studies on squill since 1741 
is given by George (12^). The active principle has not been definitely 
isolated and identified. Many of the products obtained by extrac- 
tion wdth various solvents have proved to be impure mixtures. _ In 
many instances it is not plain whether red or white squill was studied. 
George states that the active constituents of squill are (1) scillitin, 
C17H25O6, a yellow, very bitter, nitrogen-free glucoaide, slightly solu- 
ble in water (0.18 per cent) and soluble in alcohol, which was isolated 
' Reference is made by italic numbers in parentheses to " Literature cited," p. 35. 
