996 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[June 14, 1873. 
non-nitrogenous extractive matter and fat contained in it; 
it is, however, influenced by the various digestibility of 
the raw fibres. Fodder materials of the same kind, but 
of different origin, are digestible in very various degrees. 
The digestive power of one and the same animal for the 
same fodder varies little, and may, under normal con¬ 
ditions, be regarded as almost constant. The digestive 
powers of different individuals of the same species are 
slightly but not essentially different.” 
Herr Stohmann further extended his researches to the 
connection of milk-production, and other phenomena of 
metamorphosis, with nutrition. 
The amount of milk.production is dependent on the 
individuality of the animal, on the duration of the lac¬ 
tation period, on the fodder, and especially on the albumen 
contained in this,—as appeared from experiment, by in¬ 
creasing and diminishing the amount of albumen. A 
fodder which, reckoning for a constant animal weight, is 
sufficient for abundant production of milk in a large 
animal, does not meet the requirements of a small animal; 
whence it follows that a small amount of animal weight 
of a goat is more expensive to maintain than a corre¬ 
sponding quantity of a cow. The goat is, during its 
comparatively short lactation period, a more liberal milk- 
producer than the cow; since, for the same weight of 
animal, an equal supply of milk is never obtained from 
the cow. The milk-production is influenced by the 
quantity of water consumed and distributed through the 
body. Cows fed with watery fodder, green fodder, tur¬ 
nips, and the like, give considerably more milk; we also 
find nursing women drink large quantities (proportionally) 
of liquid. This shows that the production of milk is an 
essentially different process from fattening. Greater con¬ 
sumption of water, while it furthers milk-production, 
hinders fattening; milk-production demands a large ex¬ 
change of albumen, while everything that promotes this 
exchange opposes fattening. The fat contents of fodder 
have, according to Herr Stohmann, no special influence 
on the secretion of milk. Protein-stuffs, also, do not 
operate immediately, but after some time; and it would 
appear that the lacteal glands are slowly “built up” at 
the expense of the albuminous blood, and afterwards, on 
falling asunder, they give forth the milk. 
Lastly, with reference to the influence of nature of food 
on change of material ( Stoffumsatz ), Herr Stohmann has 
some propositions which closely correspond with those ad¬ 
vanced by Voit with reference to carnivora. 
“ Increase of albumen in food causes increased change 
of albumen in the body;” a statement, which, e.g., is 
proved by the following numbers from experiment: — 
Fodder. 
Nitrogen 
Absorbed by 
the G-oat. 
Nitrogen 
Excreted in 
Urine. 
Hay 
1500 grammes 
1400 
1100 
800 „ 
Linseed Meal. 
100 grammes 
200 „ 
500 „ 
800 
17'9 gi'ammes 
2.M „ 
310 „ 
411 „ 
10 - 7 grammes 
14-5 „ 
18-9 „ 
27-8 „ 
The quantity of nitrogen employed for the production 
of constituents of the body rises and falls with the in¬ 
crease and diminution of albumen in the food; a fact 
which is readily explained if one considers that the 
albumen-change increases almost proportionally to the 
nitrogen received, but not quite; so that there is an ever- 
increasing remainder for incorporation of protein in the 
tissues, and for the production of milk. 
Increase of albumen in the food acts, in the first in¬ 
stance, on the production of milk-albumen, and in much 
smaller degree on incorporation of albumen. The incor¬ 
poration and expenditure of albumen are dependent on 
the state of the body; a fact which is especially apparent 
in changing from one fodder to another, when the albumen- 
change corresponding to the new food does not at once 
come into play. The albumen-change in the body in¬ 
creases with increased water consumption. 
An incorporation of fat takes place, when with great 
quantities of albumen there are given great quantities of 
easily digestible non-nitrogenous matters. 
SAND EKOSION. 
The novel.method of engraving and boring glass, stone, 
etc., by causing jets of fine siliceous sand to impinge with 
great velocity upon the portion intended to be removed is 
illustrated in the International Exhibition at South Ken¬ 
sington by a machine invented by Mr. Tilghman, of Phila¬ 
delphia. The machine is thus described in a Report on 
Machinery and the Processes connected therewith, fur¬ 
nished to the Journal of the Society of Arts by the Rev. 
Arthur Rigg, M.A. 
“ There are two machines now in operation upon glass, 
and one at work on stone. The small machine is to ap¬ 
pearance a very plain painted box or stand—nothing of 
machinery visible. In the top of this box are two holes, 
about an inch and a half in diameter. If the wooden 
casings were removed, there might be seen below these 
holes a pipe, which descends, and is formed somewhat 
trumpet-mouthed on the outside of the bottom of the box. 
Below this mouth is a turned wooden basin. From the 
upper part of the box, on the spectator’s left hand, a pipe 
passes underneath the floor to the centre of a rotating fan, 
near the wall of the room, and therefore by this a vacuum 
can be formed in the box. As the only inlet of air is past 
the trumpet-mouthed opening, a rapid current ascends the 
pipe connected with it whenever the exhaust-fan is at 
work. From large hoppers (funnel-shaped) containing 
sand, a regulated quantity falls towards the turned wooden 
basin; in falling on the basin it is influenced by the en¬ 
tering air, is jetted from the pipe, and so strikes upon, 
say, glass covering the holes; the exposed glass is rapidly 
depolished. Where, however, an elastic substance, as 
paper, india-rubber, etc., covers the glass, no action of the 
sand takes place. 
“ If interstices or openings be formed in this elastic sub¬ 
stance, as a pattern, then the surface of the glass is re¬ 
moved in accordance with such pattern, and to a depth 
dependent upon the time of exposure, and the intensity of 
the current of air, and quality of the sand. 
“ Next to this small “vacuum” machine is a large com¬ 
pressed air-blast one, capable of acting upon a sheet of 
glass three feet broad. A design in paper or lace being 
pasted on the glass, it is laid upon endless bands, by the 
motion of which it may be carried forward. In the mid¬ 
dle of the compartment (which is glazed upon one side so 
that spectators may see the operation) provision is made, 
by a suitably-formed transverse opening, for a blast of air 
with sand. When the ordinary machinery is set in mo¬ 
tion this blast commences, the glass is travelled at a pre¬ 
arranged velocity, and in as little time as one may require 
to read this account, the ornamented glass is delivered at 
the side of the box opposite to that at which it entered. 
“ So slightly an elastic surface as the changed character 
of some of the materials used in photography suffices to 
resist the action of the sand ; hence the photographic de¬ 
sign may be etched by sand on glass. Examples of vari¬ 
ous works done by this process are on a table near to the 
machine. The third machine is in a separate building. 
It consists of a wooden table, on which the stone is laid. 
This table can be traversed impulsively in one direction, 
by the action of a Clement’s driver, on a spur wheel, and 
so motion is given to a rack. 
“ Above the table, provision is made for traversing the 
combined steam and sand jet. This is accomplished by a 
mangle-wheel motion, variable according to the breadth of 
the stone to be operated upon. By these two motions, 
transverse to each other, every portion of the stone may 
be reached. The steam and sand jet is arranged upon the 
plan adopted by Mr. Siemens, for exhausting the telegraph 
despatch tubes—the sand being admitted by an inner 
