PROGRESS IN BACTERIOLOGY.
THE science of bacteriology is comparatively new, but great advances have been made in it since its inauguration by Professor Koch in 1881. In an address before the Royal Institution of Great Britain Professor Klein declared that so far has the study of bacteria developed that it is now possible not only to count, but also to weigh, them. A postage-stamp seven-eighths of an inch long and three-fourths of an inch wide would carry 500,000,000 of the typhoid fever bacilli, and if the layer were made a tenth of an inch deep, there would13be 2,000,000,000,000. If fifteen drops of bacteria were let fall into a cup of broth, they would produce in twenty-four hours 80,000,000. The degree of refinement manifested by the bacteriologist in his researches is shown by the statement of the same authority that it is now possible to detect one part of sewage when contained in 500,000 parts of water.—Christian Advocate.