:fuLY 1, 1903.] 
Supplement to the " Tropical Agmulhmst." 
75 
nutrients of one specimen from -figures representing 
the average composition. Accordingly, in the 
more careful dietary studies, the composition of 
the food is determined by analyzing samples of 
materials actually used. Again, this method 
assumes that all the food is really consumed, 
whereas it is very plain that frequently no small 
portion is wasted in the kitchen or at the table. 
This difficulty is usually met by measuring and 
comtutiag the amounts of nutrients in the waste 
and sometimes by anal/zing samples of it. 
In preparing the results of dietary studies so 
(hat different studies may be compared, another 
difficulty appears. For example, in a family 
coDfcisting of father, mother, and two children of 
different ages the amount of food taken by each 
is by no means the same, and it would be quite 
incorrect to divide the whole amouuts consumed 
by four and call the result th3 amount used per 
person. Men, as a rule, eat more than women, 
women more than young children, and persons of 
active habits more than those who take little 
muscular exercise. A coal heaver, who is con- 
stantly using up nutritive material of muscular 
tissue to supply the energy required for his severe 
muscular work, needs a diet with more protein 
and higher fuel value than a bookkeeper who sits 
at a desk all day. It is ordinarily estimated that, 
as compared with a man at moderate or light work, 
a woman under similar conditions needs 0.8 as 
much food, and children amounts varying with 
their ages, and such figures are used to reduce the 
statistics of a dietary to the standard of one man 
at moderate work. The various factors commonly 
used in the United States in computing the results 
of dietary studies are as follows ; — 
Factors used in calculating meals consumed 
in dietary studies. 
Man at hard muscular work requires 1.2 the food 
of a man at moderately active muscular work. 
Man with light muscular work and boy 15-16 years 
old require 0,9 che food of a man at moderately 
active muscular work. 
Man at sedentary occupation, woman at moder- 
ately active work, boy 13-14, and girl 15-16 
years old require 0.8 the food of a m>iu at moder- 
ately active muscular work. 
Woman at light work, boy 12, aud girl 13-14 years 
old require 0.7 the food of a man at moderately 
active muscular work. 
Boy 10-11 and girl 10-12 years old require 0.6 the 
food of a man at moderately active muscular 
work. 
Child 6-9 years eld requires 0.5 the food of a man 
at moderately active muscular work. 
Child 2-5 years old requires 0,4 the food of a man 
at moderately active muscular work. 
Child under 2 years old requires 0.3 the food of a 
man at moderately active muscular work. 
«- ■ — 
ON THE IDENTIFICATION OF DIFFERENT 
SORTS OF MEAT BY PRECIPITATION 
WITH SERUM. 
BY M. H, VALLEE, of ALFOBT. 
It, has been recognised that the presence of 
glycogen as a means of identifying horse flesh is 
not quite satisfuctory, and that at present there 
are no chemical means known by which flesh from 
different species of animil? can be detected, 
whereas on the other hand the biological process by 
means of precipitant serums is highly valuable. 
Ohlenhuth points out that butchers' meat, no 
matter how well the carcase has been bled, alway.s 
coutniii.s a cei tain amount of blood, and he was one 
of the first to obtain from a maceration of meat in 
water a cLaracterislic precipitant. 
Pork macerated in !=erum gives a clear precipitant 
with serum from a rabbit treated by injections of 
pig's serum, w hereas this serum will not cause any 
precipitation in macerations of other sorts of meat. 
Notel used precipitant serum to recognise horse 
flesh. 
Meissner, Herbet, Kieter, and Wolff, have all 
studied the subject and published articles on it. 
The first step necessary is to obtain a solution of 
the albumen in the substance under examination 
which can easily be done with raw, smoked, or 
salted meat, but cannot with cooked, tiie albumen 
being coagulated and insoluble. The mjat sliould 
be finely minced nad macerated iu an 8 per cent, 
solution of chloride of sodium to which is added 
50 per cent carbolic acid. Meissner and Herbet 
recommend this to prevent the growth of 
micro-organisms in the solution. Meissner and 
Herbet use one part of fresh meat to 50 of saline 
solution, and one part smoked or salted to 25 of 
water, 1 have used these proportTons successfully. 
The preparation while in process of maceration 
should be kept iu a cool place for at least twelve 
hours, aud shaken from time to time. It is theu 
filtered through muslin to get rid of the material, 
aud the pink fluid again passed through a 
quadruple paper filter several times until it is per- 
fectly clear. 
If it is only required to determine if the sus- 
pected meat is horse flesh, it is only necessary to 
take 2 cc. of the filtrate, and add 1 cc. of serum 
from a rabbit that has been inoculated several 
times with horse serum. The tube is kept iu as 
cool a place as possible with a control tube to 
which no serum has bean added. The r^sulc will 
usually be seen between second aud si.\:tli hour^, 
but it is advis!ible to allow teu or twelve hours co 
elapse. If the meat is not horse flesh the solution 
will remain clear, but if, on the contrary, it 
becomiis slightly turbid in half an hour, which 
turbidity increases up to the tenth or sixteenth 
hour, the meat is horse flesh. 
If it is necessary to determine what sort of meat 
the specimen is, five tubes cmtiiiuiug the solution 
have to be used as follows : — 
I. 2cc. solution plusl cc. precipitant 
serum of Horse. 
II. 5, fi Ox. 
III. ,, ,, ,, ,, Pig. 
IV. ,, ,, ,, Dog. 
V, ,, or control tube. 
The tubes are treated as before and examined up 
to the sixteenth hour. If, for example, tubes I. 
and III. become turbid, then it may be taken for 
granted that the suspected substance is composed of 
a mixture of horse flesh and pork, 
Iu the ciae of pork the test is absolutely reliable, 
also with horse and dog flesh, butoot with beef, asox 
