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SCIENTIFIC.
are the merhants of Lawrence. I am not prepared to say who are to blame for this; but from the state of the weather at that time, the ice was expected to break up almost any hour, at the time the irons were laid. And besides, the bridge had been closed a long time before the ice broke up.
An International Electrical exhibition is to be held in Philadelphia next September, under the auspices of the Franklin Institute.
-In new industries, such as electric lighting, plating, and the conveying of electrical power through wires, a conference of this nature, where each can see for himself what is of too recent invention to be found in books, is of immense value to both science and industry.
The conference of electrical scientists which is to be held soon in this country, has made arrangements to hold their session in connection with this exhibition. Both movements are supported by the leading scientists of this country and of the Old World.
TRICHINAE SPIRALIS.—So much has been said and written of late about prohibition of the American hog in Germany and France on account of trichinosis, and it is a subject of so much importance in our own country, that it may be profitable to know something of the little parasite. The normal abode of the trichina is in the moisture of the rat and the hog, but that it is especially fond of the American hog is not true. Man simply acts as an auxiliary to the hog in its production. The first case of trichinosis observed in this country was in New York in 1864, but nothing of the habits of the trichina was known until quite recently.
During the last ten years ten thousand people have been known to have perished from this cause.
Trichinae appear as white spots in meat, but under the microscope they are seen to be worms coiled up, hence their name (Trichina spiralis.) They occur very abundantly, as many as four hundred thousand having been found in one ounce of pork. Nothing under 212 degrees Fahr. will kill them, and as it is impossible to raise the center of the ham, in boiling, to that temperature, if the meat be infected the consequences of eating are apparent. Trichinae will increase fourfold in two days, as many as one thousand eggs coming from one female in a short time, and producing as many as two hundred million trichinae in one generation. It may be remarked that five hundred thousand are enough to kill an ordinary man. An example of the great liberality of one hog in dealing out these bosom friends of his to an entire neighborhood may be taken from M. Bronardel's paper to the French Academy of Medicine. He traced the cause of the epidemic at Emersleben in Germany, to one hog that had been chopped fine and eaten raw on bread, as cheese, by a large number of persons. Between the 12th and the 19th of September, 1883, two hundred and fifty persons were taken ill; of them forty-two died. In the neighboring village of Deisdorf forty-two were affected; of them nine died. On the 19th of September the chopped meat remaining unsold was mixed by the butcher with a fresh lot and sold in the town of Nienbagen, where eighty persons were attacked, though less seriously, and none died.
Trichinosis has recently appeared in our State capital, two families having been attacked and one death resulting.
In Chicago in 1865-6 a committee of physicians on examining more than one thousand hogs in different packing establishments reported one animal in fifty infected with trichinosis.