Page:Popular Science Monthly Volume 91.djvu/286

 Mollycoddling the Microbe

Some of the deadliest germs are very deli- cate and require plenty of milk and eggs

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��HINK of cultivating deadly germs, the typhoid bacillus, for instance with as much

��care and attention to diet and environment as would be given to a delicate orchid or even to a beautiful baby! That is what is being done at the American Museum of Natural History in New York city.

tjp in one of the tower rooms there is a regular nursery for germs. They live in tubes, rows on rows of them, in neatly ar- ranged and classified wooden racks. Each tube contains a jelly, and on top of this jelly is a wrinkled mass of whitish, yel- lowish or brownish scum. In this scum are the babies — or plants, as the Museum bacteriologist classifies them.

The jelly is made up of meat, peptone, and the extract from agar, a Japanese sea- weed. Some of the germs, however, are

���fastidious and require egg; others must have blood; still others need milk and special kinds of salts. The food preferences of each particular germ are as carefully studied and compounded as are the special dishes in the diet kitchen of a hospi- tal.

Some of the bacteria will live for weeks without special attention, while others must be transferred to a fresh tube of food jelly every three days. To transfer them, the bacteri- ologist in charge simply touches the scum in the tube with a platinum needle. The bacteria adhere to the needle but readily drop off into the fresh jelly. The fact that 400,000,- 000 of the typhoid bacilli could be packed into a grain of granulated sugar will give some idea of the size of the microbes.

��Needless to say, the germ-filled tubes are han- dled with extreme caution by the examiners

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��In the yellowish, whitish or brownish scum which is to be found in each of the tubes there are millions of infinitesimal microbes feasting and flourishing on the food jelly of their choice

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