tity and quality of the food, the nutritive value of the ration, and 

 the course of life of the subject, and to record the effect observed on 

 the health and the metabolic processes in general. This work has 

 been distributed among a large number of observers, each having 

 control of a particular part of the investigation and working inde- 

 pendently. In this case, as in all of the others, it was not until the 

 figures were collated, tabulated, and studied that the tendencies 

 induced by the preservative were known, and not until then could 

 any attempt be made to determine the general effects or to draw 

 conclusions from the data. 



While it is not to be expected that the mass of compiled figures 

 presented are absolutely free from error, the general effects which 

 were produced are unmistakable, and it is believed the conclusions 

 drawn therefrom are deduced on sound principles of reasoning and 

 are based on reliable data, the marked uniformity of the analytical 

 results and the absence of contradiction in the individual data being 

 especially marked in this experiment. 



ORGANIZATION AND CONTROL OF THE EXPERIMENT. 



The twelve men who became members of the table for testing the 

 effects of formaldehyde on health and digestion were carefully exam- 

 ined before the beginning of the experiment, as in previous cases. 

 The medical history of each man was ascertained, no one being 

 admitted who was not free from organic disease or who had suffered 

 from serious illness of any kind within a year or two, who was pre- 

 disposed to any hereditary malady, or who exhibited any feebleness 

 of constitution which would make him an easy victim to disease. 

 The usual daily examinations were made of each man, the temper- 

 ature, pulse, and body weight being recorded. When any variation 

 from the normal was noticed, the observation was checked by an 

 attendant, who was always present and supervised the securing of 

 the data for the clinical and medical history; and any symptoms 

 reported were carefully considered, to determine how far such dis- 

 orders might be attributed to the use of the preservative. 



ADMINISTRATION OF THE PRESERVATIVE. 

 SCHEDULE OF ADMINISTRATION. 



This series of investigations was begun on the 12th of November, 

 1904, and concluded on the 17th of December, 1904. The fore 

 period covers ten days of observation, the preservative period fifteen 

 days, and the after period ten days. The dates of the several sub- 

 periods are given in Table I. 



[Cir. 42] 



