NATURE 
[Marcu 12, 1914 
42 
life, and no diet is complete without them. 
If the “brain, “one som ethemthree, legs) <0 aiire 
tripod of life,” is starved by a vitamineless diet 
troubles of all kinds—called by Funk deficiency 
diseases—arise, and these may end in.death. The 
muscles dwindle away, the nerves degenerate, and 
heart and bone troubles result. Their absence is a pre- 
disposing cause of tuberculosis. Vitamines are found 
in plants, and especially in their seeds. So far as is 
known at present, animals are incapable of making 
them. Animals, however, obtain them by feeding on 
plants. Thus vitamines occur normally in meat, fresh 
milk, and yolk of egg. They are soluble in water, 
and insoluble, mostly, in ether. They are thermo- 
labile, and are destroyed by exposure for 10-20 
minutes to a temperature of 120°-130° C., as well as by 
extreme dryness. Thus cattle may, following on a 
long drought, suffer from a vitamineless fodder. 
Funk regards vitamines as the mother-substance of 
ferments and hormones, and of vital importance to 
the thyroid and other ductless glands. It is thus 
evident that the diet standards of the text-books must 
be revised in the light of their discovery, which throws 
a flood of light on the milk and other food problems. 
White flours and corn flours are deficient foods because 
the vitamines have been removed in the milling pro- 
cess. 
Wherever any cereal, robbed of its aleurone or 
vitamine layer, forms the chief food of a people, there 
a deficiency disease appears. Rice is eaten by more 
people than any other grain, in the tropical regions 
of both hemispheres. The marked increase of beri- 
beri caused by eating polished rice, claiming thousands 
of victims yearly in Japan, etc., coincides with the 
replacement of the primitive whole-grain stone-milling 
by the modern steel roller. The United States 
Government has already made the polishing of rice 
in the Philippines illegal. Indian corn (Zea mais) 
is largely eaten in north Italy, the Balkan provinces, 
the southern part of the United States, Brazil, etc. 
In all these countries pellagra, which affects the skin, 
digestive organs, and mental powers, is prevalent. 
The disease could be stamped out by adding to the 
diet potatoes, one of the cheapest and most practical 
sources of vitamines. Though the tax of 32s. 6d. a 
ton on potatoes has been removed, the U.S. Govern- 
ment has at the same time closed its ports to European 
potatoes, as a precaution against the introduction of 
potato diseases, such as Spongospora, though pellagra 
is on the increase, and American potatoes are becom- 
ing dearer. 
Rickets, scurvy, osteomalazia, etc., are also deficiency 
diseases caused by the use, as the main articles of 
diet, of such vitamineless foods as sterilised milk, 
condensed milk, cornflours, starch, and sugar. The 
mixed diet of most people protects them from deficiency 
diseases. 
Vitaminous foods are fresh milk and (though less 
rich in them) pasteurised milk, whole grains, potatoes, 
carrots, and other fresh vegetables, lime and other 
fruit juices, beans, peas, lentils, and the like, meat, 
beef-tea, barley-water, yeast, and apparently cod liver 
oil The discovery of vitamines leaves the vexed 
question of the relative values of white bread, standard 
bread, etc., where it was, as the heat of the oven, 
far above that of the autoclave in milk sterilisation, 
probably destroys the vitamines of the wholemeal 
bread. 
Phaseolus mungo, L. (P. radiatus, L.), added to 
polished rice effectively supplies the removed vitamines, 
prevents beri-beri, and has long been regarded by the 
Chinese as a delicacy in the form of vermicelli. A 
veast extract is already available for a similar purpose 
in this climate. 
NO, 2305, VOU. 93) 
ATMOSPHERIC REFRACTION AND GEO- 
DETIC MEASUREMENTS.! 
MONGST the many perplexing problems with 
which geographical surveyors have to deal those 
which concern the determination of altitude are not 
the least. For purposes of practical ability, such as 
the levelling of roads or the laying out of contours 
and gradients where differential altitude is compara- 
tively small and progressive, existing methods are 
quite sufficiently scientific and accurate. It is in the 
determination of the relative altitudes of large geo- 
graphical features, where angular measurements be- 
come necessary, that there arises a series of com- 
plications due to variations in the amount and effect 
| of refraction, or in that of the plumb-line deflection, 
which have been by no means exhaustively investi- 
gated, and which introduce errors of an appreciable 
quantity. These errors are seldom of large practical 
importance, so that an investigation into their origin 
and the scientific methods of their dispersion is more 
or less matter of academic interest to that limited 
public which concerns itself with mountain altitudes 
and is generally content to accept the reading of a 
cheap aneroid as sufficient proof of the correctness of 
a value determined by triangulation. 
By the scientific geodesist, however, Mr. Hunter’s 
investigations will be warmly appreciated. The book 
before us is No. 14 of the Professional Papers of the 
Survey of India, and it contains a careful analysis of 
the chief sources of error which beset the ordinary 
estimates of the amount and effect of terrestrial re- 
fraction. The error due to refraction is usually dis- 
posed of by the assumption that the angle of refrac- 
tion bears a constant ratio to the angle contained by 
the ray of observation at the centre of the earth. 
When reciprocal observations can be taken (i.e. from 
A to B, and from B to A) this ratio can be determined, 
and it is then recorded as the ‘coefficient of refrac- 
tion,’ and is applied to other observations which, not 
being reciprocal, require to be corrected for the effect 
of refraction. This method Mr. Hunter calls a 
‘““makeshift,’”’ and it is with the object of putting the 
consideration of ‘“‘angular measurements affected by 
terrestrial refraction on a more accurate and scien- 
tific basis,” that he has deduced formule from 
his investigation which, in the concrete form of tabu- 
lated corrections, may assist in dispersing the errors 
arising from variations in the density, temperature, 
and atmospheric pressure of the air between the 
station of observation and the point observed. The 
only assumption which he makes is the natural one 
that ‘“‘layers of equal density in the air are concentric 
with the (circular) section of the earth in the azimuth 
of the ray,’’ an assumption which includes that of 
thermal equilibrium. The formula derived in chap. i. 
show that refraction depends very largely on the rate 
at which temperature changes with the height, and 
with the change of this rate, as well as on the differ- 
ential height to which the ray extends. Mr. Hunter 
confirms the accepted rule that refraction is least in 
the middle hours of the day, but he further regards its 
variations as seasonal, i.e. it is least in the springtime 
of the year. 
But when all is said and done, it is the érrors aris- 
ing from the deflection of the plumb-line (not always 
ascertainable at the point of observation), and the 
possible variation in the actual height of the point 
observed (common enough in the case of snow-capped 
peaks), which chiefly affect the accuracy of angular 
determinations of altitude, and it is probably to these 
rather than to the unequal conditions affecting the 
v “ Formule for Atmospheric Refraction and their Application to Terres- 
trial Refraction and Geodesy.” By J. de Graaff Hunter. 
