Page:The New International Encyclopædia 1st ed. v. 16.djvu/30

* PIGMENT. dinal-bird, and otliii.-, and in the 'rose' around the eyes of the grouse. It is soluble in ether, al- cohol, and chloroform, but not in acids or in pot- ash. Zoiixantliin. yellow, can be extracted by- boiling in absolute alcohol, and is a diffused pig- ment which tinges the shafts, rami, and radii of the feathers, and is possibly the same in the yel- low feet and bills of birds of prey and ducks; like zorierylhrin, it is a colored fatty oil. Turacin is a most |)cculiar pigment, detected in the red feathers of the Musophagida-, and seems to be re- stricted to these birds. It consist.* of the same elements as zoonielanin with the addition of from 5 to 8 per cent, of copper. Such pigments appear in the coloring matter of birds' eggs. See Egg. In insects the conditions arc somewhat dif- ferent, as the coloring matter is lodged not only in the scales, but in the skin or crust of the body. The pigment in most insects, as well as in the lobster, is secreted in the deeper layer of the skin, under the cuticle, and this layer is called the hypodermis. When the lobster casts its shell the soft hypodermal layer consists of cells which are filled with red and blue pigment masses. This cellular layer gives rise to the outer cuticle, which thus derives its hue, red and blue, from the deeper inner layer of color-secreting cells. In most insects the cuticle is nearly colorless, or horn-colored or honey-yenowisli. in tint. It has been found by experiments that pig- ments may be dissolved out by chemical reagents and subsequently restored by other agents. Both Coste and Urech have proved that red. yellow. brown, and black colors in the scales of certain butterflies are always due to pigments, and in a few ca.scs greens, blues, violets. puri)les. and whites arc due to the presence of pigments in the scales themselves. Dr. A. G. JIayer believes that the pigments of lepidopterous insects are derived from the Ijlood of the chrysalis. The first color to appear in the pupa or chrysalis of the Ameri- can silkworm, on which he made liis observations, is dull ycllnw oclirc or drab: this is of the hue of the blood when removed from the chrysalis and exposed to the air. Mayer has also artificially produced several kinds of pigments from the blood, which are similar in color to various markings on the wings of the imago, or advilt. He has also found that chemical reagents have the same effects on these manufactured products as on similar pigments in the wings of the liv- ing moth. As regards pigmental colors, Baer classified them into two types: diffused and granular. Pigments of the first type are diffused through the ehitin or substance of the scale, are usually present in very small amount, and include the dark pigments, most yellows, oranges, and reds, except in the Pieridfe. and the whites ( uric acid ) of the Pierid*. Baer also, contrary to the results of Hopkins, found that some of the orange and yellow pigmeuts of the Pierid* are diffuse and not granular. Granular pigments occur exclu- sively in the Picriilae and are yellow or red in color. They color the scales in which they occur very deeply. Such scales are few in number and almost without surface sculpturing. The super- position of dark-colored scales upon scales deeply tinted by yellow granular pigment may. as in Anthochaus rardamines, produce a greenish tint. Equal activity has been shown by chemico- 14 PIGOTT. biologists in the study of the coloring matter of flowers. It is now held that nearly all blue and red pigments originate from tannin ; in other words, tannin constitutes the chromogcn of the red and blue floral pigments. Keegan sliowed that the circumstances which created or influ- enced the particular tint of flowers was first chemical (the presence of quercetin in the form of rutin, etc., in the corolla ). and second, physio- logical, i.e. the possession by tlic corolla of en- ergetic respiratory and transpiratory functions, with the result that the substances contained in its cells underwent an oxidation more or less vigorous and complete. PIGMY PARROT. One of the diminutive parrots of New Guinea., of the subfamily Xasi- ternina>, which are smaller than a song sparrow. They have l>eaks like those of miniature cocka- toos, short square tails, and the nuiles have gor- geous plumage, but the fcnuiles are more soberly dressed. PIGNEROL. pA'nyc-rol'. The French name of the town of I'inerolo (q.v.). in Italy. PIGNUS (Lat., pledge). At Roman law, a pledge, i.e. something given to secure performance of an obligation. Originally, pignus could be established only in corporal things, and only by giving possession; and it conferred no right upon the pledgee except that of retaining possession until the debt was paid. Power of sale in case of the debtor's default was first introduced by contract, but eventually the power of sale became part, of the general law of pledge. Pledge of a claim against a third person (pif/iiiis twminis) was also recognized, a quasi-possession of the pledgee being established by notice to the pledgor'.s debtor. Before the close of the republican period the pledge of a thing had liccome independent of possession ; it could be established by mere agree- ment; and such a contractual lien was enforce- .■?lile against third persons. With this change pignus and hypotheca (see Hypothec atio.n) became virtually the same thing. In the Jus- tinian law piijiiiis designates a pledge or mort- gage of movable property or of a debt, while hypotheca designates a mortgage of immovable property. From the point of view of the relation of pledgor and pledgee, pipiiuf! was regarded as one of the real contraots. See C'ontr.ct. I'i 11)1 11.1 could i)e established not only by con- tract, but by will. It could also be established by levy on property in execution of judgment, and it was established in some cases by direct operation of law, as in the case of the landlord'.s lien on the efi'ects brought in by the tenant. Modern civil law recognizes as a rule no pledge of movables without possession. See Pbopebty; also B.ILMENT. PIGNUT. See E.^bthxit. PIGOTT, ptg'ot, Richard (1828?-89). An Irish journalist and forger. He passed a check- ered career on several Dublin newspapers. In 187n he was proprietor of three newspapers, which be soon sold to the Irish Land League, of which (?liarles Stewart Parnell (q.v.) was presi- dent. Hitherto a violent Nationalist, Pigott now began to vilify his former associates and to sell information to their political opponents. His famous transaction was with the Irish Loval and