INGESTION OF BEEF TEA. 159 



INGESTION OF BEEF TEA. 



The noticeable increase in metabolism found by the earlier investi- 

 gators as a result of the ingestion of flesh led to tests on animals to 

 determine the influence of extracts which consist chiefly of creatine 

 and its allied compounds. Experiments with man on this subject 

 are extremely limited in number. Beef extract (probably 15 per cent 

 water) in amounts of 12 to 18 grams per day was used in some of the 

 classical experiments of Pettenkofer and Voit 1 on their so-called fasting 

 days, but as no suitable basal value is available for comparison the 

 results of the experiments give no evidence as to the possible effect of 

 the extract upon the metabolism. In our study on the influence of the 

 ingestion of food, a study was also made of the effect of ingesting beef 

 tea. 



STATISTICS OF EXPERIMENTS. 



The series of experiments on beef tea included five experiments with 

 the respiration calorimeter at Middletown (see tables 88 to 92) and 

 two experiments with the chair calorimeter at Boston (see tables 

 93 and 94). In addition, six experiments were made with the uni- 

 versal respiration apparatus in Boston (see tables 95 to 100). The 

 results of these experiments are summarized in tables 67 and 68. 

 (See pages 135 and 136.) 



For the calorimeter experiments the beef tea was made by extracting 

 fresh beef with water; in all but one of the respiration experiments it 

 was prepared from a so-called extract of beef, a commercial product 

 being used. The composition of the beef tea is indicated in table 50. 

 (See page 124.) The method of preparation from the fresh beef was 

 as follows: 



The beef (from the top of the round) was freed so far as possible from 

 all visible fat and connective tissue, then chopped and covered with 

 cold water to extract the juices; finally both meat and liquid were 

 heated slowly to about 80 C. For a few experiments it was heated 

 only to 40 C. The liquid was carefully filtered to remove the solid 

 material and then cooled. To prepare it for the experiment the solidi- 

 fied fat was removed, and the remainder reheated to approximately 

 80 C. Salt was added to taste by the subject. 



It is obvious that beef tea, prepared from either the fresh meat or 

 the extract, would contain considerable amounts of creatine and crea- 

 tinine. 2 In some instances the analyses showed a large proportion of 

 nitrogen, particularly in the experiment of May 9, 1907, in which 6.82 



Pettenkofer and Voit, Zeitschr. f. Biol., 1866, 2, p. 459. 



2 The amount of creatine and creatinine in the beef tea used in the Middletown experiments 

 M-as determined through the kindness of Dr. Victor C. Myers, at that time assistant 

 pathologist at the Connecticut Hospital for the Insane and at present director of the 

 Laboratory of Pathological Chemistry in the New York Post-Graduate Medical School 

 and Hospital. 



