4 Transactions. 



The methods of analysis used were chosen after careful consideration 

 of the latest literature on the subject; in each determination two or more 

 results were obtained and the average figure recorded. 



It was "ound necessary to determine what changes occurred in fresh 

 meat held at ordinary temperatures to ascertain the efiect of ripening on 

 the chemical composition of the meats, no such data for mutton or lamb 

 having hitherto been recorded. With this in view, portions of the meat 

 from the freshly killed material were held at laboratory temperatures for 

 seven days, and examined periodically. It was also necessary to ascertain 

 what changes took place in the known absence of bacterial interference ; 

 for this purpose samples of the freshly killed material were mixed with 

 thymol and chloroform to inhibit the growth of bacteria without inter- 

 fering with enzyme action. Samples of the material thus prepared were 

 examined periodically up to seven days. 



Lastly, it was necessary to know what changes take place as the result 

 of known bacterial decomposition, and, as suggested by Richardson and 

 Scherubel, portions of the freshly killed materials were mixed with a 

 putrefying meat-infasion. These materials were kept for fourteen days 

 at laboratory temperatures, and examined periodically. 



The chemical results, in addition to being expressed on the basis of the 

 original meat (Table A of each chemical experiment), are also recalculated 

 to the moisture-, ash-, and fat- free basis (Table B of each chemical experi- 

 ment), because owing to the impossibility of removing exactly the same 

 amount of adhering fat from the meat, and also because of the variations 

 of the moisture-content (which will be discussed later), the results expressed 

 on the basis of the original meat cannot be directly compared as to the 

 chemical changes which have taken place during cold storage. Therefore, 

 in order to put the data on a fair basis for comparison, all the results of 

 the chemical experiments are recalculated to the moisture-, ash-, and fat- 

 free basis. It is needless to say that the variation in the amount of fat 

 found has no bearing on the present investigation, and the figures are used 

 merely as a basis in calculating the results. The amounts of nitrogen found 

 in the cold-water extract are also recalculated in their relation to the total 

 nitrogen (Table C of each chemical experiment) for the purpose of showing 

 more clearly the changes taking p'ace in the nitrogenous constituents of 

 the meats. 



Owing to the influence of enzjonic activity in animal tissues, the chemical 

 experiments also included the separation and detection of the common 

 enzymes. The results of this examination are shown in Chemical Experi- 

 ment No. 5. Determinations of the acidity of the fat, both fresh and cold 

 storage, were made, and are recorded in Chemical Experiment No. 6. 



Bacteriological experiments were carried out to determine the presence 

 or absence of bacteria on the surface and the interior of both t'le fresh 

 and frozen materials, and also to determine the influence of cold storage 

 upon bacterial life. The results are shown in Bacteriological Experiments 

 1, 2, and 3. An examination of the physical appearance and structure of 

 the frozen meats was also made. 



Discussion. 

 The Changes due to Putrefaction. 

 In order to determine the nature of the changes caused by bacterial 

 decomposition, a series of experiments were carried out to demonstrate 

 these. 



