I may say in this place that I have made all my measurements with one of Hartnack's No. 8 objectives, without collar adjustment. The camera Lucida was placed in every case at the same height from the table (ten inches); the light was also placed at the same angle and distance from the reflector, so that if there was any source of error in any direction it could not have affected the comparative measurement of the corpuscles in the least degree.

The blood, which was obtained from some fifteen individuals of both sexes, from children to adults, and from nearly as many dogs, comprising a spaniel, a Newfoundland, two or three terriers of different ages, besides several mongrels of various breeds, was dried upon glass in the usual manner, and then drawn and measured as shown in my figures.

There is no appreciable difference in measurement between fresh corpuscles and those dried in thin layers on glass. I have chosen those dried on the glass as being the most convenient to draw from.

Instead of measuring separate corpuscles, as they pass under the micrometer, I have adopted a method which seems not only free from error, but which in criminal trials enables me to show the court and jury the result of my investigations, instead of their having, as heretofore, to depend upon the mere abstract statement of numbers.

In every case the miscroscope might be taken into court to verify the accuracy of the drawings, as I have already done in private before several eminent judges and lawyers of this city, in a case of blood corpuscles scraped from the blade of a knife, and restored and preserved on a glass slide.

On making the drawing, in the first place a horizontal line is drawn along the margin of a piece of thick paper-to this a perpendicular line is let fall, forming with the base line the two sides of a rectangular figure. A spot is next selected on the glass slide where the corpuscles are spread in a single layer and are as little deformed as may be, and where one of the squares may be filled without the necessity of much change of place of slide or paper. I next proceed to pile up the corpuscles, so to speak, beginning in the angle formed by the meeting of the lines, until I have a pile of seven, and so proceed with pile after pile until I have seven piles, containing forty-nine corpuscles in all; this is shown in the first plate. The glass slide is not moved, the paper being moved only

at right angles to bring the corpuscles into lines. I have drawn some eight or ten thousand blood corpuscles of all kinds, and placed in twenty-four tables 1176 human and dog corpuscles, giving 1176 measurements of each.

The magnifying power used gives 1275 diameters; that is, a superficial area of 1625625.

Each of the plates are dated when drawn (as, per example, the one engraved) and marked on the back as follows:

Plate I. "Blood of female forty years old. Corpuscles taken without selecting, as they occur on the slide, 1275 diameters, June 1st 1876.

"Blood of dog terrier, three years old, taken as above."

The plate shows the relative size of the corpuscles, that of the dog being the smallest.

The average measurement of blood corpuscles from my tables is: Human blood, 3236 of an inch, 0077.74 millimeters.

Gulliver, the authority followed by Drs. Carpenter, Flint, Richardson and others, gives:

Iluman blood, go of an inch, 0079.40 millimeters.

Schmidt, another authority, gives:

Human blood, 37%, of an inch, 0077.76 millimeters.

Dog's

In the engraved plate, No. 1, the human blood was from a female of the age of forty, and the dog's blood was that of a terrier three years old, as before mentioned.

The measurement of the seven rows of human blood corpuscles measured both ways-that is, horizontally and perpendicularly, making fourteen measurements-gives an aggregate of 37.5 inches, which is below the average, this being 38.4 inches. The dog's blood measures 34.7 inches, which is above the average, this being 33.9 inches.

I

may remark that these drawings were made by me, mathematically accurate on the engraved block; should the print show any difference it will be due to the swelling or shrinking of the paper, and of course this could not affect the proportions.

Divide 37.5 inches by 98, double the number of corpuscles in

1

the table; this gives .3826, the diameter of one. Divide this sum by the magnifying power 1275 gives 3333 of an inch = .007614 millimeters. The dog's blood in the plate measured in the same manner gives whole measurement 34.7 inches. One corpuscle, .3551 3590 of an inch =.007680 millimeters.

I find thus far from all the measurements I have made that if we compare the smallest table of human blood with the largest of the dog's blood, the difference is recognisable at a glance; and if we further, as recommended by Dr. Richardson, use a higher magnifying power, this difference will be still more marked. I give two diagram tables of this kind, showing a magnifying power of 2932 diameters. (Plate II.)

It will be seen how closely my measurements agree with the authorities, and I may say in passing that I had drawn and measured nearly all these tables previous to comparing any of them with these authorities.

In still further pursuing the subject, I propose to give drawings of different forms of blood corpuscles liable to be called in question in criminal trials; and also the result of experiments with reference to distinguishing different kinds of blood taken from spots on various substances; as, per example, from knife-blades, knifehandles, linen, silk, leather, wood, &c., &c., and also to show how far it is possible to distinguish blood spots from other stains, even where the blood corpuscles have been entirely destroyed.

It will be seen at once that by this method of presenting the matter, evidence can be brought in such a manner before those whose province it is to decide, as to preclude the possibility of error on their part.

It will also be seen that, although my measurements do correspond closely with the authorities, thus going to prove their general accuracy; still, were not this the fact, it would not affect the result, as this depends upon the comparison of the corpuscles with each other, without regard to their absolute mea

surement.

The blood slides were all prepared in precisely the same manner; the corpuscles were figured under precisely the same conditions of the instrument, light, &c. As I have mentioned before, I have made nearly ten thousand drawings of blood corpuscles since I began this investigation. These have been made from fourteen different kinds of animals, and certainly the blood corpus

cles of no one of these approach as near to those of man as do those of the dog.

I here rest the question "whether the red blood corpuscles of man and the dog in their normal condition can by the aid of the microscope be distinguished from each other?" How far this can

be done with blood spots scattered on various substances, as mentioned before, remains for future discussion.

The third plate has been drawn since the above was written. It was thought well to give it, as it shows the form the blood corpuscles frequently assume when dried on glass and like substances. The square covers an area about equal to the average of my measurements. If we count two of the corpuscles which project over the lines as occupying the space of one on the inside of the square, we shall find that they number forty-nine, as when formed of single corpuscles arranged in order, as in my tables; this fact shows that but little, if any, shrinkage occurs, even when the corpuscles are forced out of shape from any cause.

CHICAGO, Ill.

VOL. XXIV.-72

R. U. PIPER, M. D.

RECENT AMERICAN DECISIONS.

Supreme Court of Vermont.

JAMES FERRITER ET AL. v. J. M. TYLER ET AL.

It is the right of the directors of the public schools to prescribe the hours of attendance of the pupils, and to make a proper system of punishments for absence, &c.

In doing this the public rights and convenience must govern, without regard to the wishes or convenience or private preferences of parents or others.

This rule applies to the attendance of the children on public or private religious worship on week-days during the prescribed hours for school. Such purpose does not excuse violation of the rules of the schools.

IN equity on bill and answer. The complainants were members of the Catholic Church in the village of Brattleborough, and it appeared that on June 4th 1875, the priest of the said church, acting in behalf of the complainants, sent to the respondents, who were the prudential committee of that school district, a request that the Catholic children might be excused from attendance at school on "all holy days," and especially on that day, being holy Corpus Christi day. To this note the committee replied that the request could not be granted, as it would involve closing some of the schools and greatly interrupting others.

It further appeared that about sixty Catholic children, by direction and command of their parents, were kept from school to attend religious services on said 4th of June, being, as stated in the bill, "holy Corpus Christi day." A few of them applied for admission to the schools in the afternoon of that day, and all, or nearly all, so applied the next morning, when they were told by the committee that, as they had absented themselves without permission, and in violation of the rules of the school, which they well understood, they could not return without an assurance from their parents, or their priest, that in future they would comply with the rules of the schools, the committee assuring said children, and many of their parents, and also the priest, that if said schools would not again be interrupted in like manner they would gladly admit said children to them; that said priest and parents refused to comply with such proposal, and claimed that on all days which they regard as holy they may, as matter of right, take their children from the schools without any regard to the rules thereof.

The bill prayed an injunction against the committee, defendants