In past times identification of criminals who had passed through the hands of the law was compassed by branding, imprinting by a hot iron, or tattooing with an indelible sign, such as a crown, fleur de lys or initials upon the shoulder or other part of the body. This practice, long since abandoned, was in a measure continued in the British army, when offenders against military law were ordered by sentence of court-martial to be marked with "D" for deserter and "B.C." bad character; this ensured their recognition and prevented re-enlistment; but all such penalties have now disappeared. (A. G.) IDEOGRAPH (Gr. [Greek: idea], idea, and [Greek: graphein], to write), a symbol or character painted, written or inscribed, representing ideas and not sounds; such a form of writing is found in Chinese and in most of the Egyptian hieroglyphs (see WRITING). IDIOBLAST (Gr. [Greek: idios], peculiar, and [Greek: blastos], a shoot), a botanical term for an individual cell which is distinguished by its shape, size or contents, such as the stone-cells in the soft tissue of a pear. IDIOM (Gr. [Greek: idiôma], something peculiar and personal; [Greek: idios], one's own, personal), a form of expression whether in words, grammatical construction, phraseology, &c., which is peculiar to a language; sometimes also a special variety of a particular language, a dialect. IDIOSYNCRASY (Gr. [Greek: idiosynkrasia], peculiar habit of body or temperament; [Greek: idios], one's own, and [Greek: synkrasis], blending, tempering, from [Greek: sygkerannusthai], to put together, compound, mix), a physical or mental condition peculiar to an individual usually taking the form of a special susceptibility to particular stimuli; thus it is an idiosyncrasy of one individual that abnormal sensations of discomfort should be excited by certain odours or colours, by the presence in the room of a cat, &c.; similarly certain persons are found to be peculiarly responsive or irresponsive to the action of particular drugs. The word is also used, generally, of any eccentricity or peculiarity of character, appearance, &c.