but this flame is never propagated back through the narrow tube into the bromine bottle.  The precaution may be taken, however, of plugging this narrow tube with a little glass wool, which renders any inconvenience from this cause quite impossible.  By this method a large quantity of bromine may be rapidly converted into hydrobromic acid without any loss of bromine, and the operation when once started can be allowed to proceed without any further attention.—­Chemical News.

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SAPOTIN:  A NEW GLUCOSIDE.

By GUSTAVE MICHAUD.

Achras Sapota, L., is a large tree scattered through the forests of Central America and the West Indies; its fruit is often seen upon the Creole dinner table.  This fruit is a berry, the size of an orange, the taste of which suggests the flavor of melon, as well as that of hydrocyanic acid.  The fruit contains one or two seeds like large chestnuts, which, if broken, let fall a white almond.  This last contains the glucoside which I call sapotin.

I obtained sapotin for the first time by heating dry raspings of the almond with 90 per cent. alcohol.  While cooling, the filtered liquid deposited a good deal of the compound.  Since that time I have advantageously modified the process and increased the amount of product.  I prepare sapotin in the following way:  The almonds are rasped, dried at 100 deg.  C. and washed with benzene, which takes away an enormous quantity of fatty matter.  The benzene which remains in the almond is driven put first by compression, afterward by heating.  Then the raspings are exhausted with boiling 90 per cent. alcohol.  The solution is filtered as rapidly as possible, in order to avoid its cooling and depositing the sapotin in the filter.  As soon as the temperature of the filtered liquid begins to fall, a voluminous precipitate is seen to form, which is the sapotin.

In order to purify it, the precipitate is collected in a filter and expressed between sheets of filter paper.  When dry it is washed with ether, which takes away the last particles of fatty and resinous matter.  The purification is completed by two crystallizations from 90 per cent. alcohol.  At last the substance is dried at 100 deg..

The sapotin separates from its alcohol solution in the form of microscopic crystals.  When dry, it is a white, inodorous powder.  Its taste is extremely acrid and burning.  If the powder penetrate into the nostrils or the eyes, it produces a persistent burning sensation which brings about sneezing and flow of tears.  It melts at 240 deg.  C., growing brown at the same time.

It has a laevo-rotatory power of [a]_{j} = -32.11, which was determined with an alcoholic solution, the aqueous solution not being sufficiently transparent.

It is very soluble in water, easily soluble in boiling alcohol, much less in cold alcohol, and insoluble in ether, chloroform and benzene.  Its alcoholic solution is precipitated by ether.