The above evidence indicates that pneumonia is a general infection in man, thus resembling its mode of action in some of the susceptible lower animals. Blood cultures in recent years have confirmed this evidence. Difference in technique, and varying severity of the epidemic-studied accounts for the wide difference in results.

Sittman (2) in 1894, demonstrated the organisms in six out of 16 cases of pneumonia. In two of these they were only found in smear preparations, the cultures remaining negative. Three of the four positive cases ended fatally, but only three of the 12 negative cases died. He employed 5 c. c. of blood, making agar plates.

Kühnau (3) used 10 c. c. of blood with agar plates. He obtained positive results in one out of nine cases. This case ended fatally, as did two of the negative cases.

Kohn following the method of Sittman, made cultures from 32 cases, with nine positive results; seven of these died while only two of the negative cases ended fatally.

Casati (4), by means of animal inoculations, obtained positive results in 25 consecutive cases. Their presence in the animal was demonstrated by microscopical examination and cultural test. In some of his cases, positive results were obtained as early as the second day.

White (5), using 5 c. c. of blood in agar and bouillon tubes, obtained positive results in three out of nineteen cases, all of these ending fatally. Seven of the negative cases terminated fatally. He Inade repeated cultures in two of the fatal cases, the results being negative on the third day, but positive on the second day preceding death; in the third case positive results were only obtained 24 hours before death. The number of colonies per c. c. of blood varied from ten to eighty.

Sello (6) examined 48 cases with 12 positive results, ten of these ending fatally; 27 of the negative cases recovered, nine dying.

Prochaska (7), using 5 to 10 c. c. of blood in bouillon and also in agar slants, reports positive results in every case. In all, 40 cases were examined, and in 36 of these, pure cultures of the diplococcus pneumoniæ were obtained, in two mixed with staphylococci, and in two cases the diplococci tended to grow in long chains, which he refers to as the streptococcus pneumoniæ. He made only a single culture in each case. His technique, apparently, only differs from that of others in that he allowed a longer period of time for the development. The identity of the germ obtained was verified in each case by animal inoculation. Eight of the series died. In two positive results were ob

tained on the second day of the disease, nine on the third day, and five cases after the eighth day. In one case of protracted pneumonia, on the twenty-first day, a normal temperature being present for three days preceding the test.

Cole (8) reports 30 cases with nine positive results, all of these ending fatally; four of the negative cases died. The earliest time at which cultures were obtained was three days before death. Cultures were made from two of the negative fatal cases; in one, two days and the other eight hours preceding death. He used as a culture medium litmus milk, adding from 8 to 10 c. c. of blood to 150 c. c. of the media.

With the exception of the cases reported by Prochaska and Casati, the results are fairly uniform. Omitting these two series, the total number of cases examined was 154, with 38 positive results, or 24 per cent, about the same proportion of positive results as have been obtained in typhoid. The field is still new, and the total number of cases reported are few, and I believe the results of future experiments while perhaps not entirely supporting Prochaska and Casati, will show a much higher percentage of positive results than has been obtained up to the present time. Casati's results with animal inoculations are suggestive. Daily cultures should be made if posible, employing the plate method, so that we might determine how early a bacteriemia appears, and the number of germs per c. c. of circulating blood; this latter might be of special value in the prognosis which will be referred to later.

As a diagnostic means blood cultures will probably be of very little value. The signs and symptoms of croupous pneumonia are so characteristic that errors in diagnosis are few, and it is only in central or atypical cases that blood cultures, if positive, could furnish valuable diagnostic aid. Control blood cultures should be made from healthy individuals, at seasons when pneumonia is epidemic, as the germ is found in the saliva of a large percentage of healthy people in certain seasons of the year, and it is possible that bacteriemia may be found to exist in some of these.

From a prognostic standpoint, cultures will probably be of value. Omitting the series of Prochaska and Casati, 87 per cent of the positive cases died, and only 22 per cent of the negative cases. The presence of a bacteriemia in pneumonia has been considered by the investigators as a grave omen, indicating a severe infection. Prochaska, who obtained positive results in all cases, denies that it is of prognostic value, as they are found in the mild as well as the severe cases.

This,

however, does not mean necessarily that the germs are as abundant in mild cases, in fact other experimenters have proved that they are not; as a large per cent of negative results testify. It is true that with more perfect cultural methods the prognostic value may be lost, unless we are able to obtain the number of germs present per c. c. of blood, which could be easily carried out with suitable solid media.

REFERENCES.

I. Fraenkel and Reiche, Zeit. für klin. Med. 1894 Bd. 25.

2. Sittman. Deutsch-Archiv. für klin. Med. 1894 Bd. 53.

3. Kühnau; Zeit. für; Hygiene; Bd. 25.

4. Casati; Jahrsbericht. für; Path. 1893.

5. White; Jour. Exper. Med. IV.

6. Sello. Zeit. für klin. Med. Bd. 36; 1898.

7. Prochaska. Deutsches. Archiv. f. klinische Med. 1901; Bd. 70. 8. Cole; Bull. of the Johns Hopkins Hospital, June, 1902.

100 STATE STREET.

PHOTO SKIAGRAPHY.

BY EDWARd r. moras, M. D., CHICAGO.

(ABSTRACT.)

Photo skiagraphy introduces a new art that seems destined to prove of special utility to clinical, legal and illustrative medicine.

Aside from its interesting, practical usefulness to physician and patient, a photo skiagram becomes indispensable as part of the record of a case, and it provides the physician or surgeon with the best legal, as well as scientific, evidence obtainable.

There is current the impression that only the very dense structures, such as bones, concretions, stones, foreign bodies and the like, come within the reach of x-ray photography. A glance at any of the photographs exhibited destroys that impression. The accompanying engraving, though not as fine for details as the original photo skiagram, is substantial evidence that the softer tissues and parts may be successfully photographed. I have made very good photographs of deep and superficial muscles and tendons, and even of a small pelvic (ovarian) growth.

It may be of some interest to state how photo skiagraphy originated, assuming that the idea had not been made practical before. While treating some cases of arthritis deformans, the results obtained suggested the theory that the chemic or pathologic process operating Chicago Medical Society, March 4, 1903.