69 
nization in working on antiproteid immunization. He fed rabbits 
daily for a number of weeks with egg albumin by means of a stom- 
ach tube. The rabbits’ serum was examined every eight days. After 
twenty-four days it developed the power to precipitate egg albumin. 
Metalnikoff ° reports that he attained immunization by feeding one 
animal with the blood of another. He f£d horse’s blood to white 
rats. After three or four feedings no agglutination or hemolytic 
action of the rats’ blood upon the horse’s corpuscles was noted. In 
one week the action appeared feeble and increased to decided strength 
after one or two months. 
GUINEA PIGS MAY BE SENSITIZED BY FEEDING HORSE MEAT. 
After demonstrating the possibility of rendering guinea pigs sus- 
ceptible by feeding them with horse serum, we next fed a series with 
horse meat. The following series was fed with indefinite amounts of 
horse meat, both fresh and dried ground up with carrots, as guinea 
pigs do not like fresh horse meat and must be very hungry in order to 
eat it. 
G. P. No. 242. Fed 9 days on horse meat from Feb. 15. Injected March 9 into peritoneal 
cavity with 6 c. c. antitoxic horse serum (Natl. IX, 17), 24 days after first and 15 days 
after last feeding. Symptoms; recovered. 
G. P. No. 237. Fed 9 days on horse meat from Feb. 15. Injected March 10 into peritoneal 
cavity with 6 c. c. antitoxic horse serum (Natl. IX, 17), 25 days after first and 16 days 
after last feeding. S^unptoms; recovered. 
G. P. No. 238. Do. 
G. P. No. 239. Do. 
G. P. No. 240. Do. 
G. P. No. 244. Do. 
G. P. No. 241. Fed 9 days on horse meat from Feb. 15. Injected April 5 into peritoneal 
cavity with 6 c. c. antitoxic horse serum (Natl. VIII, 18), 49 days after first and 40 days 
after last feeding. Symptoms?; recovered. 
G. P. No. 243. Fed 9 days on horse meat from Feb. 15. Injected March 13 into peritoneal 
cavity with 10 c. c. aqueous extract dry horse meat, 26 days after first and 17 days after 
last feeding. No symptoms. 
As the above series was fed with indefinite amounts, another series 
of guinea pigs was placed upon definite weighed amounts of horse 
meat. Four grams of the dried ground horse meat were mixed with 
fresh carrots and fed to the pigs daily. Almost all the pigs placed 
upon this diet did poorly, their coats became shaggy and the animals 
lost weight. 
G. P. No. 246. Fed 4 gm. dried horse meat daily from March 15 to 28. Injected March 28 
with 6 c. c. antitoxic horse serum (Natl. VIII, 18), 13 days after first and 0 day after last 
feeding. Symptoms?; recovered. 
G. P. No. 4562. Do. 
a Metalnikoff, — : Ueberhamolytisches Serum durch Blutfutterung. Centblt. f. Bakt., v. 
29, 1901, p. 531-533. 
