The Juice.

A known quantity of the juice as first expressed from the bag was evaporated down on a slow fire. The reaction remained acid during the

evaporation. It did not seem to form a jelly at any stage in the evaporation, and merely thickened to a stiff syrup. In this state it did not grow moulds, although weaker concentrations readily did so and also readily underwent fermentation with brewers' yeast.

After standing some weeks the syrup became crystalline, but the crystals were mingled with so much precipitated material and pigment, and recrystallization was so slow, that it was difficult to obtain a quantity of the purified crystalline substance. The small quantity that was obtained evidently consisted of glucose, as shown by its physical appearance and its osazone crystals. That laevulose was also present in the crude syrup was, however, clearly shown by the following observation: The syrup was extracted with hot alcohol, clarified with charcoal, and examined in the polarimeter in watery solution; the result was laevo-rotation; and the solution gave very distinctly Seliwanoff's test for laevulose. That this solution contained a mixture of dextro- and laevo-rotatory sugars was proved by the fact that in a clear solution containing 15.5 per cent. reducing-sugar as estimated by Allihn's method the rotation corresponded to only 2.3 per cent. laevulose.

The syrup was also tested for galactose by the mucic-acid test, but with negative results, so that no evidence was found of the presence of raffinose.

The ash of the juice was found to contain a considerable amount of iron salts.

Two experiments were made in order to test whether the concentrated juice contained any of the poisonous properties of the other parts of the plant. In one a known amount of the crude syrup was diluted and administered by stomach-tube to a rabbit. No symptoms followed. The dose corresponded to about 54 grammes of the juice as expressed from the ripe fruit. It would correspond to about 2 lb. to a human adult.

In the other an attempt was made to extract any tutin that might be present. The quantity used would correspond to about 1 kilogram (2.2 lb.) of the original juice. It was covered with acetone in a stoppered bottle, and left for three weeks, with frequent stirring and shaking. The extract so obtained was heated to drive off the acetone, dissolved in water, and administered to a rabbit. No symptoms resulted which could be ascribed to tutin. The animal became practically anaesthetized and unconscious, but recovered fully in a few hours. The symptoms were probably due to some acetone or acetone compounds which had not been completely removed by the heating.

From these experiments it seems extremely unlikely that the juice contains any tutin.