A jury found defendant guilty of involuntary manslaughter (Pen. Code, § 192, subd. 2), and the court denied her motion for a new trial. Judgment was suspended, and defendant was admitted to probation for a term of three years on the condition that she serve one year in a county detention facility. Defendant appeals.
Defendant was a psychiatric technician at the state hospital in Modesto in charge of a ward of 50 mental patients. One of the patients in defendant’s ward was Grace Belill, a 71-year-old woman suffering from involutional psychosis, a mental condition that commonly causes a patient to refuse to eat. On October 12, 1955, a doctor at the hospital noted in Miss Belill’s record that if necessary she was to be spoon fed. On October 14, 1955, at the noon meal, Miss Belill was not eating, and defendant spoon fed her. During the feeding the patient collapsed and shortly thereafter died. The cause of death was asphyxiation from the aspiration of stomach contents.
The gravamen of the charge against defendant is that she used improper methods and excessive force in spoon feeding the decedent. The People sought to prove that defendant’s conduct constituted either criminal negligence or a misdemeanor and that the misdemeanor consisted of a violation of either section 242 (battery) or section 361 (treatment of insane persons) of the Penal Code. The jury was given in *414 structions appropriate to each of the People ⅛ theories, including an instruction in the statutory language of section 361, and returned a general verdict of guilty.
Defendant contends that the provisions of section 361 are so vague and uncertain that her conviction thereunder is a denial of due process of law. “ [A] statute which either forbids or requires the doing of an act in terms so vague that men of common intelligence must necessarily guess at its meaning and differ as to its application violates the first essential of due process of law.”
(Connally
v.
General Const. Co.,
Section 361 provides: “Every person guilty of any harsh, cruel, or unkind treatment of, or any neglect of duty towards, any idiot, lunatic, or insane person is guilty of a misdemeanor.” The phrase “neglect of duty” has an accepted legal meaning. It means an intentional or grossly negligent failure to exercise due diligence in the performance of a known official duty. (See
Rapaport
v.
Civil Service Com.,
*415
The trial court correctly interpreted section 361 as requiring a specific intent (see
People
v.
Vogel,
We conclude that the words “harsh” and “unkind” do not provide an ascertainable standard of conduct or a workable standard of guilt and that insofar as it purports, without further definition, to make “harsh” treatment and “unkind” treatment criminal offenses, section 361 of the Penal Code is void for vagueness. The court’s instruction relating to section 361, given in the language of the statute, was therefore erroneous, and in view of the conflicting evidence as to the nature of defendant’s acts and the general verdict, the error must be deemed prejudicial.
(Oettinger
v.
Stewart,
The fact that a statute is unconstitutional in part does not necessarily invalidate the entire statute. The remaining parts of the statute may be preserved if they can be separated from the unconstitutional part without destroying the statutory scheme or purpose.
(Danskin
v.
San Diego Unified Sch. Dist.,
Defendant contends that as a matter of law the evidence that the decedent’s death was caused by an act of defendant does not support her conviction. The evidence viewed most favorably to respondent discloses that defendant fed the decedent three tablespoons of cubed, creamed potatoes. She held the decedent’s head back by grasping her hair with one hand and fed her with the other. At intervals during the feeding defendant covered the decedent’s mouth and nose with a towel. Another attendant was holding the decedent’s arms, and at some time during the feeding or immediately thereafter a hospital inmate sat on the decedent’s lap. At some time during the feeding the decedent wiggled her legs. After the third spoon of food was put into her mouth the decedent collapsed. Efforts to revive her failed, and shortly thereafter she died. Dr. Miller, who performed the autopsy, testified that she found lodged in the decedent’s trachea and bronchi three to four tablespoons of partially digested food, white in color and creamy in substance. The cause of death was established as asphyxiation from the aspiration of stomach contents. Dr. Miller testified that no food was found in the decedent’s stomach and explained on cross-examination that the decedent must have swallowed the food as it was fed, regurgitated, and then aspirated the regurgitated matter. At the time of her death, the decedent was suffering from chronic inflammation of the gall bladder with stone formation, and a quantity of “bile-tinged” liquid, characteristic of a gall bladder attack, was found in her stomach. Decedent also had coronary arteriosclerosis ; the inside diameter of the anterior descending branch of the left coronary was reduced in size to that of a pin point.
It is defendant’s contention that there is no proof whatever that any act of hers caused the decedent to regurgitate and *418 aspirate tbe stomach contents and that, on the contrary, there is evidence that these events were not caused by defendant’s acts. The district attorney asked Dr. Miller the following hypothetical question:
“If a person is sitting on a chair, and her head is held back by the hair of her head so that her face is looking up towards the ceiling—also, her arms are being held, and another person is sitting on her lap—and then an amount of food is placed into the person’s mouth, and she is resisting the food—and then a towel is placed over her mouth and her nose is also being held for a period of time, and then the person slumps over and thereafter expires, and approximately four heaping tablespoons of food is found lodged in the trachea; now, Doctor, based upon this hypothetical question, what would be the cause of death, Doctor?”
Defendant objected to the question on the ground that it omitted a material fact in evidence, namely that the food found in the decedent’s trachea was partially digested. The court overruled the objection, and Dr. Miller answered, “The cause of death would be due to asphyxia, caused by obstruction of the trachea with food.” The objection should have been sustained. The undisputed evidence was that the food was partially digested. This fact was essential to a consideration of causation, for it showed that the food had been in the stomach and must have been regurgitated and that, therefore, it was not aspirated directly as it was put into the decedent’s mouth.
It is obvious that the hypothetical question and Dr. Miller’s answer did not advance the inquiry into what caused the decedent to regurgitate and aspirate her stomach contents. Dr. Miller had previously testified to the cause of death. Her answer to the hypothetical question merely repeated that testimony, and her answer was obviously based on only two of the facts in the question, namely that the decedent died and that approximately four tablespoons of food were found lodged in her trachea. On cross-examination Dr. Miller testified that she did not know what caused the decedent to regurgitate, that it was possible that either the decedent’s heart condition or her gall bladder condition could have caused it, but that she thought these possibilities improbable. Dr. Toller, a defense witness, was presented with the same hypothetical set of facts presented to Dr. Miller. It was his opinion that none of the circumstances disclosed therein, either singly or collectively, could have caused the decedent to regurgitate *419 and aspirate her stomach contents. He testified that it was possible that the regurgitation might have been caused by the decedent’s heart condition or gall bladder condition. He suggested as a third possibility that the regurgitation might have been caused by the decedent’s revulsion because of her mental condition to the thought of eating.
Thus, the testimony of the expert witnesses supports defendant’s contention. If the jury rejected the opinion evidence, however, they could infer that the manner in which the decedent was fed was at least a contributing cause of her regurgitation or that, even if the regurgitation was not caused by an act of defendant, her placing the towel over the decedent’s mouth and nose preventing the vomitus from escaping was the cause of the decedent’s aspirating the regurgitated matter. The latter inference is weakened by the fact that neither the time at which the decedent regurgitated nor the time at which the' towel was held over her mouth and nose was established and also by the fact that it was not shown that the vomitus ever came high enough into the throat to be expelled through the mouth. We cannot say as a matter of law, however, that either of these inferences is unreasonable.
Defendant contends that the court erred in qualifying as competent witnesses several mental patients in the state hospital at Modesto. All, of these patients were in the ward over which defendant had supervision, and some of them had histories of insane delusions relating to food and to persecution by hospital personnel. Much of the evidence most damaging to defendant is in the testimony of these patients. We deem it unnecessary to discuss the witnesses individually, for their testimonial qualifications may be changed at the time of a new trial and would have to be reexamined at that time. Our review of the record, however, indicates the desirability of our reviewing the rules governing the qualifications of an insane person as a witness.
Section 1321 of the Penal Code provides, with exceptions with which we are not here concerned, that the rules for determining the competency of witnesses in civil actions apply also to criminal actions. Section 1880 of the Code of Civil Procedure provides: “The following persons cannot be witnesses. 1. Those who are of unsound mind at the time of their production for examination. ...” This section, however, does not impose an absolute disqualification on insane persons. As was said in
People
v.
Tyree,
The question to be determined is whether the proposed witness’s mental derangement or defect is such that he was deprived of the ability to perceive the event about which he is to testify or is deprived of the ability to recollect and communicate with reference thereto.
(People
v.
Ives,
The language of section 1880 is addressed to the time at which a witness is produced for examination, and there is language in several cases suggesting that insanity at the time of the event witnessed is not a matter for consideration in the determination whether or not a proposed witness is competent to testify. (See
People
v.
Harrison, supra,
It is universally recognized that the competency of a witness is to be determined by the trial court in the exercise of its judicial discretion.
(People
v.
Ives, supra,
Defendant contends that the court erred in allowing two prosecution witnesses to testify, over defendant’s objections, that defendant used improper methods and excessive force in feeding the decedent the morning meal on the day of her death and on several other occasions. Defendant contends that the only purpose of this evidence was to prejudice the jury against her and that it should have been excluded.
“ It is settled in this state that except when it shows merely criminal disposition, evidence which tends logically and by reasonable inference to establish any fact material for the prosecution, or to overcome any material fact sought to be proved by the defense, is admissible although it may connect the accused with an offense not included in the charge.”
(People
v.
Woods,
The People were attempting to prove that defendant was guilty of a willful and unlawful use of force upon the person of the decedent. (Pen. Code, § 242,
supra.)
Defendant’s intent was clearly in issue, and her treatment of the decedent on other occasions was relevant to prove the nature of her relations with the decedent and her intent at the time of the offense charged.
(People
v.
Palassou,
Defendant also contends that the trial court erred in excluding from evidence coroner’s verdicts relating to six other deaths from the aspiration of stomach contents, which occurred at the state hospital at Modesto in 1955. Defendant sought to show by these records that the other deaths occurred naturally and to prove thereby that this decedent’s death was not caused by any act of defendant. The court did permit defendant to adduce testimony that mental patients suffering from involutional melancholia are predisposed to regurgitation and that the records of the Stanislaus County coroner’s office disclosed six deaths in the county in 1955 from the aspiration of stomach contents, all of them occurring at the state hospital in Modesto. The court excluded the coroner’s verdicts, however, on the grounds that their admission would involve inquiry into an excessive number of collateral issues, namely the circumstances surrounding each death. It was for the trial court to determine whether the probative value of the offered evidence was outweighed by the necessity of inquiring into collateral issues. (Code Civ. Proc., § 1868.) We find no abuse of discretion in the exclusion of the coroner’s verdicts.
*423 Other alleged errors and defendant’s contention that the district attorney was guilty of misconduct need not be considered, since the occurrences complained of are not likely to attend a new trial.
The orders denying a new trial and admitting defendant to probation are reversed.
