6io SCIENCE PROGRESS 



with fresh raw tomato-juice).* Tomato puree prepared by 

 simmering tomatoes in their own juice at 80-90° C, straining 

 the thickened juice and seaHng in cans, had lost still more. In 

 this case, the simmering took about i\ hours, and the canning 

 involved further heating at 100° C. for 5-10 minutes ; about 

 half the original amount of water had been driven off : 5 c.c. of 

 this juice (equivalent to 10 c.c. fresh) had only the same anti- 

 scorbutic effect as 1-5 c.c, of the raw juice. The original juice 

 had thus been reduced in anti-scorbutic value by 85 per cent. 



It has been found impossible as yet to test the vitamine 

 contents of jam, for the experimental animals cannot tolerate 

 the amount of sugar that would be necessary in giving jam 

 rations. It is probable, however, that the anti-scorbutic 

 value — if any — to be found in preserves depends upon the 

 time taken in boiling the fruit, and also on the nature and ripe- 

 ness of the fruit. There is little evidence on the latter point, 

 but it seems probable that over-ripe fruit has less anti- 

 scorbutic value than unripe or barely ripe fruit : and it is a 

 well-known maxim that only sound fruit should be used for 

 both bottling and preserving, 



8. General Considerations. — Methods such as the above are 

 especially necessary at times when fresh food is for any reason 

 difficult to obtain, but even at other times much harm may be 

 done by the common method of providing stews which are 

 kept hot for indefinite periods of time. Numerous occasions 

 arise when this is the most convenient form of providing the 

 principal meal of the day, as in catering for camps, hospitals, 

 and prisons, and other institutions. It must be remembered 

 that adverse results may follow a diet poor in vitamines, such 

 as general debility, weakness, and apathy, with low resistance 

 to infective diseases, when no sign of any specific disease can 

 be found. Such a condition has, in fact, been reported in 

 certain students' hostels in China, ^* 



There are, however, also cases of outbreak of scurvy on record 

 which have been traced to continual over-cooking of an other- 

 wise adequate vegetable and meat ration. Two are quoted 

 in the Report of the Medical Research Committee,^* pp. 65, 66. 

 Scurvy broke out in a camp in Scotland in the spring of 191 7, 

 and eighty-two men were affected. At the time potatoes were 

 scarce, but the ration contained a fair proportion of fresh 

 meat and 2 oz, of fresh swedes were available daily. These are 

 amongst the most potent anti-scorbutic vegetables we possess, 

 and, if cooked satisfactorily, should have afforded considerable 

 protection daily. The cause of the outbreak was investigated 



* The loss was due to the combined effects of bottUng and storing, but we 

 had no means of estimating the age of the bottle. The puree was prepared, 

 canned, and tested at once. 



