A statement of all the distinctions be- tween what is to be regarded as hearsay and what is to be deemed original evidence would extend this article too far. The general principle is that the mere declara- tion, oral or written, of a third person, as to a fact, standing alone, is inadmissi- ble. Res geste. But where evidence of an act done by a party is admissible, his dec- larations made at the time, having a tend- ency to elucidate or give a character to the act, and which may derive a degree of credit from the act itself. are also admis- sible, as part of the res gestæ; 9 N. H. 271; 93 U. S. 465; 116 Ind. 278; 79 Ga. 631; 112 Mo. 374; 128 Ill. 545; 95 Mich. 412; 82 Tex. 516; 18 Fed. Rep. 156; 148 Pa. 566; 21 How. St. Tr. 514; Steph. Dig. Ev. §§ 2, 7. So, declarations of third persons, in the presence and hearing of a person, which tend to affect his interest, may be shown in order to introduce his answer or to show an admission by his silence, but this species of evidence must be received with great caution: 1 Greenl. Ev. 236. Confessions of guilt in criminal cases come within the class of admissions, pro- vided they have been voluntarily made and have not been obtained by the hope of favor or by the fear of punishment. And if made under such inducements as to ex- clude them, a subsequent declaration to the same effect, made after the inducement has ceased to operate, and having no con- nection with the hopes or fears which have existed, is admissible as evidence; 17 Ν. Н. 171. Actions as well as verbal declata- tions may constitute a confession, and the same rule as to admissibility applies to both; 98 N. C. 595. There is, however, a growing unwillingness to rest convictions on confessions unless supported by corro- borating circumstances, and in all cases there must be at least proof of the corpus delicti, independently of the confession; 1 Whart. Cr. Law, §683; Cooley, Const. Lim. 385; Tayl. Ev. 744. See ADMISSIONS; CON- FESSION; RES GESTE. Dying declarations are an exception to the rule excluding hearsay evidence, and are admitted, under certain limitations in cases of homicide, so far as the circum- stances attending the death and its cause are the subject of them. See DECLARA- TION; DYING DECLARATIONS. Opinions of persons of skill and experi- ence, called experts, are also admissible in certain cases, when, in order to the better understanding of the evidence or to the solution of the question, a certain skill and experience are required which are not ordi- narily possessed by jurors. See EXPERT ;