#### Frederick A. Luning, impleaded with William R. Luning, Pl’ff in Error, *vs.*State of Wisconsin, Def’t in Error.

Where, on a trial, the counsel for the defendant asks a witness a question involving scientific opinions, in a matter whore he professes skill, if it be isolated and not coupled with any other proposition, except that which is purely scientific, it is propor evidence to ,be received. But the more language of books of science, without the adoption of the principles contained therein, by the actual experience of the witness, is of no more avail than the reading of the 'books themselves, wherein the principle is laid down. The reading of books of science, is evidence of nothing more than the opinions of the authors. The recitations of such opinions are not legal evidence. And besides, where a witness has been questioned and has given his evidence upon matters which have fallen under his own observation, and which he claims to be matter of ' fact, it becomes immaterial, and hence, of no moment for him, on .his direct examination, to testify to scientific authorities, in justification of the opinions previously testified to by him.

It is wholly within the discretion of the Court, to hear or reject the reading of scientific books, oq the trial of q qqusq.

*265Error to the Circuit Court of Dodge County.

The indictment against the plaintiff in eiror here, was before this Court, at the January term thereof, 1849, upon exceptions taken on the trial at the Circuit, and the judgment had on such trial was reversed. In accordance with the reversal of this judgment, the same indictment came on for ti'ial at the April Circuit for Dodge County, 1849.

The plaintiff in error took several exceptions to the ruling of the Judge, touching the rejection of the evidence offered by him, on the defence, and as to the admission of testimony on the part of the State; but the following exception seems to be the only one noticed or decided upon by this Court. The counsel for the plaintiff put the following interrogatory to James P, Whitney, a practicing physician of the city of Milwaukee, to wit; “Is it not a well ascertained fact in medical science, that the malaria spokeu of, will not cross a stream *1 to*be followed up with proof of the fact from the scientific knowledge of the witness that ditches have been expressly made for the purpose of shutting out a malarious region .of country from a salubrious one; and with proof from the same knowledge, that such has been the effect of such ditches; and that such ditches have prevented the crossing of malaria into salubrious regions, where it had previously crossed from such as were malarious.” To the putting this question, or to the answer to be given thereto, the prosecuting attorney for the State objected, because the.witness could not testify to anything but facts within his own knowledge. Upon this objection, the presiding Judge gave his opinion that it was well taken, and ruled that the question should not be put. To this ruling and decision of the Judge, the. counsel for the plaintiff excepted,

*266Various evidence was offered on the part of the State, tending to show, in the opinion of the witnesses, that the erection of the dam and the raising of the waters of Cedar Creek, at Cedarburgh, had, by means thereof created disease and an unwholesome atmosphere; and this was sought to be repelled by the plaintiff in error, by the reading of scientific books upon the subject of malaria, coupled with oral evidence. ■ Touching which proofs, various exceptions were taken, which, inasmuch as the Court has not specially noticed them, it is not deemed necessary to enlarge the statement of the case, by enumerating them.

*■Holliday,*fon Pl’ffin Error.

, *'Brown, Aliy. Gen.,and A. D. Sitúth,*for Def’tin Error.

On the part of the plaintiff in e'rfor, it wa's coto tended, ■in addition to the exceptions above noted, that ‘the Territorial Statutes of the'State, making provision for the 'erection of mill-dams, and securing such like rights ’to ¿persons who, under the provisions of the Statutes shall •erect them, are clothed wúh a protection against a crirft-linal prosecution for the effects or consequences which may follow or ensue the erection, touching the influence it may have upon health, or the annoyance which might individually result therefrom; that so far as the jurisdic-diction of the State is concerned in the exercise of infliction criminally, for an erection of a mill-dam, its power is *functus officio,*touching all cases where the Statutes have been complied with in obtaining the right of making the erection; th'at the remaining and only 'right of redress to individuals whose health was affected nonseqde'n'Có of *267the erection, was a prosecution civilly, for such injury; that they could not usurp the power or name of the State, to prostrate that, which by the State had been authorized to be constructed, though individual injury should ensue-. And to this point was cited 12 *Pickering's Rep*478.

On the part of the State it was insisted that the Statutes giving authority for the erection of mill-dams, did not deprive the State of the exercise of its powers to prosecute criminally, to procure the abatement of a nuisance* which was unendurable, or which injuriously affected the health of the neighborhood; that the grant of the right was in subserviency to the injury it might inflict; and if injury to the public ensued, the State should exert its power to relieve the suflering individuals from harm, especially where health was concerned. To this general-doctrine reference was made to *Roscoe’s Evidence, pi*659.

And to the point of admitting the evidence of Doctor Whitney, upon that point upon which the exception was taken, and in affirmance of the rejection of that evidence, by the sitting Judge, the counsel cited *1st Greenleaf, p**440; 5 *Carrington and Payne,*219.

*By the Court*

Stow, C. J.

This is the second ap-> pearance of this cause in this Court, a new trial having been had since the January term. The only ground on; which the former judgment was reversed, was that thé opinions of unlearned persons, not physicians, as to the in-, fiuence the mill-dam in question had in-producing the disease complained of, were allowed to go the to jury.

Of the various questions now raised, it is not necessary* nor is it proper, to consider but one; all the others hav-*268jng been distinctly passed upon in the previous decision, for we wish it to be understood that where a question, «properly before this Court, has, after argument, been solemnly decided here, it is not open for *discussion;*the Legislature, and not the Court, must correct the error if there be any.

The Court below refused to allow the following question to be put to the medical witness, Whitney: “ Is it not a well ascertained fact in medical science, that the malaria spoken of, will not cross a stream1? to be followed up with proof of the fact from the scientific knowledge of the witness, that ditches have been made for the express purpose of shutting out a malarious region of country from a salubrious one; and with proof, from the *same knowledge,*that such ditches have prevented the crossing of malaria into salubrious regions, where it had previously crossed from malarious ones.” This question was objected to, by the counsel for the State, on the ground that the witness could not testify to any thing but facts within his own knowledge. For a proper understanding of *the*question and proposition, it is necessary to examine the previous testimony of the witness.

The question itself, stripped of. the accompanying proposition, is a very proper one, apd probably would not have been objected to. Similar scientific principles were given in evidence, by the witness, and well settled results were aiiowed to be shown by medical books. For instance: Whitney says, “if a malarious region was covered with water, so long as it was kept submerged, it ■would prevent the extrication of malaria.” “ Stagnant water in a malarious region will- not tend to create disease.” “ If water becomes stagnant, in a district not ■malarious, there would be po danger from the water.” *269“ The scum spoken of, absorbs the very poison that the water might otherwise evolve.” “It is generally conceded by the medical faculty, that still water will retain?, malaria.” Now, these are all scientific principles, or ascertained results, and do not vary in character from the question proper, proposed to be put. How far, then, does the accompanying proposition modify it *1*Was it intended that the witness should testify from his “ scientific knowledge,” derived from medical and philosophical works, as to facts, or rather examples and particular experiments therein related 1 or was he to speak from his “ scientific knowledge,” derived from his personal examination of certain ditches *%*If from the latter, the question was in no wise different from many others which were permitted to be answered. If from the former, the testimony would have been mere hearsay. It would have been receiving as evidence of facts, mere - recitals from books, not only unaccompanied with the sanction of an oath, but at second hand. The witness appears, by the bill of exceptions, to have been allowed repeatedly to testify to scientific facts, derived from his personal experience and observation. As, “ from my own observation, I know that the west and northwest are malarious countries.” “ Water, in passing over a dam, or water-wheel, will evolve any volatile particles it contains.” “ During the latter part of the summer, for the past two years, nearly every famil)’, at the commencement of the rapids, four miles abové Milwaukee, have had fever and ague and remittents.” From this examination alone, aside from the objection of the District Attorney, “ that the witness could not testify to *facts*not within his own knowledge,” it is manifest that *270the purpose of the question and proposition was, to extract front the witness evidence of *facts,*derived from his “ scientific,” not his personal' knowledge; or, in other words, that he was to swear to facts, the existence of which he only knew from his reading; and this, upon po principle of evidence, could be admitted. Aside from this, taking this witness Whitney’s testimony as a guide, it is ^ apparent that the question was no way material, as he had already testified that the decomposition of neither vegetable, aqueous, or animal matter, nor all or either combined, would produce malaria; thus showing, as far as his testimony was to bo relied on, that the disease did not proceed from the mill-pond. The testimony was, therefore, immaterial, and properly rejected. This is the only ground of error that can properly be considered. But as we permitted an argument in regard to the use of what are called scientific books, on a trial, we repeat what wo before said on this subject: It is a matter wholly within the discretion of the Judge, and is not the subject of a writ of error. An extreme case may be supposed, in which the discretion of the judge, both in the admission and exclusion of books, might be so abused as to require correcting. But this is very far from such a case. A liberal use of medical books seems to have been allowed.

Judgment of the Circuit Court affirmed.