connection, namely, that the average size of the corpuscles varied sensibly within a short time, in one recorded case within a period of three hours, the microcytes having within that time entirely disappeared. Without further reference to the literature upon this subject, which would occupy too much space, the attention of the reader is invited to the accompanying series of measurements and plates of the blood of patients suffering from a variety of diseases. The diagnoses of the diseases of those patients, who were inmates of the Cook County Hospital, were taken from the daily records of the attending physicians having charge of the patients. The diagnoses of those cases from the South Side dispensary were made by the physicians in charge at the time. The diagnoses of the two cases of pseudo-leucocythæmia were made by Dr. Lester Curtis, of this city, to whom the author desires to express his obligations for material assistance by way of references to the literature upon the subject. The blood measured was in every instance either drawn by the writer in person, after an inspection of the patient, or by some one in his immediate presence, and it is believed that the diagnoses can be relied upon as correct.

4. As to the effect of fasting, we desire to make especial reference to the study by Dr. Lester Curtis of the blood of Mr. John Griscom, made during a prolonged fast in the year of 1881, which will be found reported in full in the proceedings of the American Association for the Advancement of Science, vol. 30. This study is very instructive, but lack of space precludes any extended quotations therefrom. Suffice it to say that the general conclusion to be derived from a perusal of this paper is that the effect of fasting is, among other things, to diminish the size and number of the red blood-corpuscles. A great many very small corpuscles were found in the blood of this subject, some as small as

the 1-12000 and 1-20000 of an inch in diameter. This observer also states that during this study he repeatedly saw blood-corpuscles subdivide and form themselves into two circular red blood-corpuscles in the field of the microscope.

It is well known that various drugs also effect the size of the red blood-corpuscles, but inasmuch as the writer has no observations of his own on this subject, he contents himself with a general reference to the literature upon the subject.

The bearing of these observations upon medico-legal cases involving the identification of blood by the measurement of red corpuscles is obvious. In such cases the specimen submitted for examination is usually, if not always, presented in the form of a clot which, as above stated, may and probably has been subjected to a multitude of variable factors. So long as these factors and their effects are unknown it seems to the writer the height of temerity to attempt to identify the blood; and in the present state of scientific knowledge for an expert to attempt such an identification without a precise knowledge of the existence and and effect of all these factors is, in the words of Dr. Woodward, to render scientific experts more dangerous to society than the very criminals they are called upon to convict.

Figures No. I, II, and III, appear at pages 161, 162, and 163, respectively, of this JOURNAL.

No. VI. 100 corpuscles of human blood from a healthy adult. Zeiss 1-18, etc.
Slide No. 14. Largest 9.32 m.; smallest-6.73.; mean 7.85 m.

No. VII. Blood of two puppies two days old, 100 corpuscles from slide 6 and 200 from slide 9. Zeiss 1-18, etc., as above.

Slides Nos. 6 and 9 1-2.

1st 100, largest corpuscle-10.18 m.: smallest corpuscle=5.70 m.; mean size-8.30 m. 2d 100, largest corpuscle 10.70 m.; smallest corpuscle-6.39 m.; mean size-8.23 m. 3d 100, largest corpuscle- 9.67 m.; smallest corpuscle-6.39 m.; mean size-8.13 m. Mean of the 300-8.22 m.

No. VIII. (On next page.) Blood of two puppies eight days old, roo corpuscles from slide No 7 and 300 from slide No. 1o. Zeiss 1-18, etc., as above.

No. IX. Blood of puppy eight weeks old, 300 corpuscles from the same slide. Zeiss 1-18, etc., as above.