4 BULLETIN 1265, U. S. DEPARTMENT OF AGRICULTURE 
live steam was used, from the instant the steam was turned on. Ex- 
posure of the material to the scalding medium was practically 
instantaneous. 
The analytical part of the work was carried out as follows: 
Samples were taken of the materials under study, both before and 
after scalding in boiling water (or test solution) and after ex- 
posure to live steam, and then were subjected to careful quantitative 
analysis. Analyses were also made of the water (or solution) after 
the scalding was done, and where chilling in cold water was prac- 
ticed this water too was examined. The total dry matter lost in the 
scalding process and in the chilling was determined by the evapora- 
tion of aliquot portions of the water, which were brought to dry- 
ness over calcium oxide, in a vacuum chamber at 100° C. Sugar, 
protein, and ash determinations were made of the aliquot portions, 
according to the methods of the Association of Official Agricultural 
Chemists (J). 
The procedure with the raw and with the treated samples was 
as follows: A convenient quantity was weighed out, care being 
taken to get representative samples, and 95 per cent ethyl alcohol 
was added to give an alcohol concentration of 75 to 80 per cent. 
After partial extraction, this alcohol was filtered off through an 
extraction thimble, and more 95 per cent alcohol added. This was 
repeated several times, and finally the residue was transferred to the 
extraction thimble and the extraction completed in a Soxhlet ap- 
paratus. In this way, the greater part of the extraction was com- 
pleted in the cold, so that the use of the Soxhlet apparatus was re- 
quired only for the removal of the last traces of soluble material. 
The sugars were determined from the extract, and the polysac- 
charides from the alcoholic insoluble portion. Except where other- 
wise stated, the methods used were those of the Association of Offi- 
cial Agricultural Chemists (3). 
In addition to the analytical work, studies were also' made of the 
effect of the different methods of preliminary treatment upon the 
appearance, flavor, and other qualities of the canned product. These 
matters will be considered in more or less detail in the discussion of 
experiments upon specific food materials. 
The vegetables and fruits used were grown specially for the pur- 
pose at the Arlington Experiment Farm, near Rosslyn, Va. 
EXPERIMENTS WITH SPECIFIC FOOD MATERIALS. 
SPINACH. 
In these experiments both the fail-planted and the spring-planted 
spinach were used. 4 The plants were in a state of vigorous growth 
just preceding the flowering period. Occasional small embryonic 
flower clusters were observed. The material was gathered in the 
field between 9 and 10 a. m. and handled at once, the tests being 
completed within 2 to 3 hours after bringing the spinach from the 
field. 
The older leaves and older portions of stems were trimmed away 
as usual, and the fresh, crisp material weighed. Experiments were 
then made upon this materia] as follows: 
♦Considerable variation in composition of the material \v;is noted, the sugar and total 
solids being greater in the Call-planted than in the Bpring-planted spinach. 
