242 THE VITAMINES 



Givens and McClugage (664) found tomatoes more resistant in this 

 respect, at least in relation to storage after drying, since after three 

 months, the activity was still retained. Subsequent cooking experi- 

 ments appear to have not been made, but are not particularly impor- 

 tant inasmuch as tomatoes may also be used raw. Shorten and Ray 

 (665) dried various kinds of vegetables in the sun, and investigated 

 their vitamine B and C content. The results showed that vitamine 

 C of carrots, onions, and cabbage were still present in sufficient 

 amounts for guinea pigs. Spinach, on the contrary, lost this prop- 

 erty. We find no statements here to the effect of ageing and subse- 

 quent cooking. Falk, McGuire and Blount (666) studied the ferments 

 of dehydrated vegetables. They found them inactivated and pointed 

 out the similarity to the resistance of the vitamines. Givens and 

 McClugage (I.e. 657) published a very careful investigation upon the 

 drying of potatoes. Taking their work as a whole, we find that when 

 potatoes undergo a series of treatments, the individual effects are 

 summed up, resulting in a totally inactive product. If the potatoes 

 are boiled, steamed or baked and then dried, an inactive product 

 is obtained, as a rule. Drying alone does not have this destructive 

 effect. The vitamine was least affected when the potato was baked 

 in the jacket (perhaps on account of absence of air) and then dried. 

 Addition of acids before treatment did not have the desired effect. 

 Potatoes dried in vacuum also lost considerable activity. We have 

 already seen that quick drying at high temperatures is less destructive 

 than gradual drying at low temperatures. Ageing and subsequent 

 drying were not investigated, although it is clear from what has 

 already been said that vitamine C of potatoes is not resistant. 



CANNING 



This subject too has not yet been extensively investigated. We 

 believe that for this question, the foodstuffs may be classified in two 

 groups those used raw, and those to be cooked before consumption. 

 We find the conditions here similar to those in drying. Bigelow (667) 

 described the problems arising in canning. Different sources of 

 supply give rise to different conditions so that general conclusions 

 can hardly be drawn as yet. Hess and Unger (668) found that canned 

 tomatoes still showed a splendid antiscorbutic action in children, and 

 adopted this antiscorbutic in their children practice; it is specially 

 suitable for institutions since the expensive orange juice may be 



