1866 .] 
AMERICAN AGRICULTURIST. 
147 
Arbor Vitae, Red Cedar, Norway and White 
Spruce, White, Scotch, Austrian and Stone 
Pines, and Hemlock. The nut-bearing trees 
have generally so long a tap-root that they are 
dilQcult to transplant, and it is recommended to 
plant them where they are to grow. They are 
best planted in autumn, or in early spring, if 
they have been kept through the winter in sand. 
It unfortunately happens that with the excep¬ 
tion of the Evergreens, few of the seeds of the 
trees in this list arc to be had of the dealers. 
Ash, Larch, Catalpa, Honey Locust, Linden, 
and Sugar and Ash-leaved Maple, we find in 
the catalogue of one of our principal seeds¬ 
men. The seeds of the Silver Maple and Elm 
are ripe the latter part of May, or early in June, 
and should be collected and sown at once. 
The seed of Evergreens is best sown in a bed 
surrounded by a frame, and so arranged that it 
can be shaded; no heating material is required, 
but the soil should be fine, light, and rich. 
The shading is best done by a slat-work of laths. 
If sown in an open bed, cover the surface with 
leaves or light hay, which is to be removed as 
soon as the plants are up. The requisite shade 
may be given by sticking leafy brush upon the 
south side of the bed. The seeds should be 
coveyed with but a very slight layer of fine soil. 
TOE eOHJSEEKDILIDo 
Parasitic Animals in Pork. 
{Trichina spiralis.) 
BY THOMAS HAIGH, M. D. 
[Various accounts have recently appeared in the 
daily, and other papers, of a disease, caused by eating 
pork that was infested by a mieroscopic animal. 
Under the head of Triehinosis, and Triehinadisease, 
some alarming and somewhat sensational state¬ 
ments have been made. As these have abundant 
foundation in fact, and thinking it best that our 
readers should know just what causes the disease 
in question, we present an account of the Trichina, 
prepared at our reqirest by Doct. Thomas Haigh, of 
the N. Y. College of Physieiaus and Surgeous.-EDS.] 
To the Editor of the American Agriculturist : 
Your request for a popular account of Trichina 
is cheerfully complied wit h. Tfie daily papers have 
already made the publie .aequainted with the faet 
that in some parts of Europe, in Germany especial¬ 
ly, the Trichina disease has prevailed to an alarm- 
Fig. 1.— TIilCHIXA CTSTS. 
ing extent, and the number of oases reported in this 
country show that it exists here to an extent, whieh, 
though not to a degree to cause alarm, is sufficient 
to demand attention. The disease is eaused by a 
microscopic animal, and the points which interest 
your readers are, what tlie animal is, how it is in¬ 
troduced into the system, and how it may be 
avoided. The existence of the animal has long been 
known, and it has been found in the llesh of persons 
who had died of widely different diseases, and in 
whom, before death, its presence had not been 
suspected. The animal is called Trichina spiralis, 
and has been noticed by Owen, Virchow, and other 
European writers, from time to time during the last 
thirty years. The most complete account of it will 
be found in a paper by Prof. John C. Dalton, of the 
N. Y. College of Physicians and Surgeons. This 
paper was published in the Transactions of the N. 
Y. Academy of Medicine, and I am allowed by its 
author to use his drawings in illustrating this article. 
The Trichiues arc fonnd in the muscles of man 
and of swine, enclosed in small sacs, or cysts, which 
Fig. 3.— MAGNITTEn TRICHINA, 
are imbedded among the muscular fibres. These 
cysts are l-30th of an inch long, and 1-lOOth of an 
inch broad; they taper at each end, and are usually 
prolonged at each extremity into a very fine thread¬ 
like appendage. Figure 1 shows these cysts as they 
appear in a magnified fragment of muscle. Each 
sac, or cyst, contains a single Trichina,—rarely two, 
—coiled up in a spiral form, making about three 
turns, so that the head is nearly opposite to the 
tail. It is a round worm l-38th of an inch long, 
and 1-620 of an inch in thickness. When magnified 
about 200 times, it appears as in fig. 3, which shows 
its structure so clearly, as to require no further 
description. As far as is known, the animal is sex¬ 
less. The cyst which contains the animal is believed 
to be formed from a minute blood vessel, which by 
the presence of a foreign body like this parasite, 
becomes changed and mostly obliterated. The 
cysts in the human muscle do not always have the 
long appendages of figure 1, but appear like figure 3. 
Tlic number of these animals is sometimes 
astonishing. They have been found so abundantly 
in ham that the number was estimated at 85,000 to 
the cubic inch, and they have been found to be 
nearly as numerous in human muscle. This brief 
description, with the figures, will give a sufficiently 
clear idea of the parasite, as it is found in the hnman 
muscle and also in the swines’ muscle. 
The manner in which it is introduced into the 
human system, is this : When pork, infested with 
Trichines, is taken into the stomach in a raw, or 
imperfectly cooked state, the sac containing the 
little worm is broken up by the process of digestion, 
and the animal is liberated from its imprisonment. 
It awakes from its dormant condition, rapidly devel¬ 
ops, and in a period of 8 or 10 days it brings forth 
its young alive. The young Trichines, which arc 
produced in great numbers, immediately penetrate 
the walls of the intestines, and getting into a blood 
vessel, are conveyed along by the blood to all parts 
of the body. They are finally lodged in the capil¬ 
lary blood ves¬ 
sels, where they 
gradually become 
encysted, or clos¬ 
ed in, by the 
change in the ves¬ 
sel, as already 
noticed, and in 
this condition they lie dormant for an indefinite 
length of time. The perforation of the intestines 
by such a multitude of worms, as well as the 
presence of so many minute foreign bodies in the 
minute blood vessels produce serious disturbance, 
though not always fatal consequences. 
The Trichina is an animal which only develops 
and, as far as yet known, reproduces itself in the 
intestines of, and afterwards lies dormant a long 
Fig. 3.— TRICHINA CYST. 
time in the muscles of man and of swine. It now 
remains to show how it finds his way into the flesh 
of swine. It is believed that of those which 
develop in the human intestines, only a small part 
bring forth their young, but that a large share of the 
full grown ones pass off in the foeces, and are thus 
enabled to find their way to the stomach of the pig, 
where they produce young, which are distributed 
through the muscular tissue of that animal, in the 
same manner as they are introduced into that of man. 
Trichines, then, come into the human system 
through eating pork, and as that meat forms a large 
share of the animal food of our laboring popula¬ 
tion, it becomes important to know how to dis¬ 
tinguish infested meat from that which is free. Un¬ 
fortunately this can be done only by the aid of a 
microscope, or at least a good magnifier. Where 
the animals have been for a considerable time en¬ 
cysted, they may be seen more plainly than those 
recently introduced, as the cysts become white 
from a deposit of calcareous matter. The figures 
show the appearance of well defined cysts, but the 
recently introduced parasite can only be found by 
those accustomed to microscopic observations. 
Unfortunately the salting and smoking of meat 
do not destroy the Trichincs, and most of the cases 
of sickness caused by them have been traced to the 
eating of raw, smoked liam. It is probable that 
the parasite cannot live when long exposed to the 
temperature of boiling water. AVhen a ham,is 
boiled whole, it Is probable that the interior of it 
docs not become heated to the boiling point, and 
that the Trichincs in the center may remain alive. 
Broiling and frying, as they are generally done, do 
not heat the meat through with sufficient thorough¬ 
ness to destroy the parasite. As a precaution, all 
who eat pork in any form should take especial care 
that it is thoroughly cooked. The only positive se¬ 
curity is, to obstain from pork altogether. From 
what has been said of the manner in which the 
parasite finds its way into the stomach of the pig, 
it wilt be seen that swine kept in pens run much 
less risk of becoming diseased than do those which 
are allowed to range at will. 
About “Plated Ware.’’ ■ 
When silver is dissolved in nitric acid and mixed 
with cyanide of potassium, a clear liquid is produced 
which contains the silver in the form of cyanide of 
silver. If the two wires from a galvanic battery be 
inserted into this liquid a little distance apart, the 
current of electricity that passes through the liquid 
from one wire to the other, decomposes the cyanide 
of silver. The pure silver metal goes to one of the 
wires and is deposited on it in a solid form. This 
takes place at every point where the wire touches 
the fluid containing the silver in solution. The 
silver is deposited in inconceivably small atoms, in¬ 
numerable millions of them in every second. In a 
single minute enough of these atoms will bo laid 
on to present to the eye a perfect coating of pure 
silver, that will completely hide the ware. If a 
larger piece of metal, as a fork, spoon, or teapot be 
attached to the wire and immersed instead of the 
wire, every point of jthe larger metal touched by 
the liquid will receive the coating of silver. As 
long as the article is in the solution and the battery 
in action, the depositing of the silver will go on. 
The practical point we wish to bring out is, that 
the” silver is deposited in such small particles, or 
“atoms,” that the coating will appear perfect, 
though the thickness may be thinner than the ten- 
thousandth part of the thickness of a sheet of 
paper. To the eye the appearance will be the same, 
whether the silver coat be only a millionth jiart of 
an inch in thickness, or a heavy coat that will en¬ 
dure hard wear for mouths, or years. A wholesale 
dealer of this city, who supplies manufaeturers of 
pl.ated ware with materials, noticed that one of 
them was buying a great quantity of lead, and in¬ 
quired the reason. The answer of the purchaser 
was, that he made plated ware for the gift enterprise 
men, (such as we described on page 86 of the March 
Agriculturist, under the head of a “Swindling 
Shop”). The lead is moulded into form, and then 
