Ihc RURAL. NEW-YORKER 
623 
The Vitamines In Our Green Victuals 
Vegetables and Fruits as Food. 
R elative VALUES.—The relative values of the 
different vegetables and fruits as sources ot 
fat-soluble and water-soluble vitamines had been de- 
lermined only in a very rough way when I wrote 
last Summer about these essential constituents of 
food. Prof. Mendel and I have since completed a 
number of experiments designed to show the rela¬ 
tive content in both these vitamines of a number of 
the more commonly used vegetables and fruits. As 
these experiments were conducted under carefully 
controlled conditions and have now just been com- 
lileted, the editor of The II. N.-Y. has asked me t<> 
give his readers an account of them. In the mean¬ 
time Steenbock and his associates at the Wisconsin 
Experiment Station have published an account of 
investigations directed to the same end. which partly 
cover the same ground as ours, but also include some 
vegetables which we have not yet tested. 
METHODS OF INVESTIGATION—Since the 
By Thomas B. Osborne 
Part I. 
conclude that a still smaller Quantity might not have 
been sufficient, but we can conclude that such food 
products contain more of the vitamine than do those 
which when fed in the same proportion prove insuffi¬ 
cient. Our experiments were conducted according 
to the second plan, because when two or more ani¬ 
mals fail from a total lack of the vitamine in their 
diet we do not know that equal quantities of the 
vitamines will restore both animals. 
THE FAT-SOLUBLE VITAMINE.--Several sets, 
each of three young rats of the same age and size, 
were put on a diet which had been proved to be en¬ 
tirely adequate in respect to everything except the 
fat-soluble vitamine. Each rat was kept in a sepa¬ 
rate cage, so that we knew just how much of the 
filial, as well as of the vitamiue-containing product, 
stored tu normal growth and health by giving them 
one-lialf gram of butterfat each day. 
BUTTERFAT STUDIES.—One set which had one- 
tentli gram of butterfat daily grew to large size, 
over 300 grams, and showed no sign of any deficiency 
in their food during nearly a year. When move but- 
terfut was then added to their diet no change in 
their condition resulted. Evidently so little as only 
one-tenth gram each day was all they needed. This 
is the smallest quantity we have ever fed. How 
much less would have sufficed must be learned from 
a new series of experiments with smaller quantities. 
The present experiments, however, show that a very 
small quantity of butterfat furnishes enough fat- 
soluble vitamine for normal growth and maintenance 
during a very large part of the natural life of the 
albino rat. These experiments afford a basis for 
comparison of the amount of fat-soluble vitamine 
furnished by the several vegetables, of which one- 
I liiimh uf h'orJi/-Jiahhi'fj Chirl’rnf) Enjopivfi the S’ J'in. 163 
chemical nature of vitamines is still entirely un- 
Irnow n there i- no way whereby food products can 
chemically analyzed and their vitamine content 
1 a-! mined and compared. The only way in which 
,lie relative vitamine.content of foods can lie estab¬ 
lished is by observing the effect of definite quan- 
"ben fed to animals. We can either give the 
"linial a vita mine-free diet, and when it fails to 
i- 1 "" and show tlie other signs of bad nutrition 
"bl a small weighed quantity of the vitamine-con- 
tuiuing food, and then note the least amount needed 
promptly to restore it to normal health, or we can 
~ 1 '' b daily from the outset of the experiment a 
'"'ill quantity of the vitamiue-containing food and 
lontinue the experiment until the animal fails, 
11u'iedproving the quantity of vitumiire given to be 
Im ' sllli| ll. or. il it dues not fail for a longtime, prov¬ 
ing it to be sufficient, lu this latter case we cannot 
ii ale. 1'or one set no addition was made to this 
diet, these animals thus serving as controls for the 
other sets. To each rat in each of the other sets 
one-tenth of a gram of one or another of the veg 
etablc products to be tested was fed daily apart from 
the foods, an excess of which was kept before them 
all of the time. The relative value of the different 
vegetables was determined by the length of time 
elapsing before the rats began to decline in weight 
and develop diseased eyes. When they reached this 
stage one-half gram of butterfat was added to the 
diet, in every case this restored them to health and 
vigorous growth, thus proving that their had condi¬ 
tion was caused by a lack of the fat-soluble vitamine. 
The set of rats to which no fat-soluble vitamine had 
been given from the beginning of the experiment 
ceased to grow within about two mouths, and after 
losing considerable weight they were prompt!} re 
tenth gram also was icd daily under otherwise ex¬ 
actly the same conditions. The set to which one- 
tenth giam of diied cabbage leaves was given each 
day did not fail until a month later than those which 
had no fat-soluble vitamine. aud these likewise re¬ 
covered when butterfat was given. The white leaves 
of the cabbage head evidently contain relatively lit¬ 
tle fat-soluble vitamine, though they probably do 
contain some. I liese results are in harmony with 
recently published experience of steenbock and Dross 
of the Wisconsin Experiment Station. 
BREEN LEAi ES.—As examples of the green 
leaves, those of Alfalfa, clover, grass and spinach 
were fed in one-tenth gram daily doses of the dried 
leaves. All of the animals grew extremely well for 
nearly a year, and when butterfat was added to their 
diot iio marked effect was observed. These experi¬ 
ments showed that these dried green leaves, weight 
