1885.] 



MICROSCOPICAL .JOURNAL. 



179 



up in the air attached to kites, and exposed 

 at definite heights. He found a far greater 

 abundance of pollen grains in the upper 

 air than below. 



— At the Inventions Exhibition in Lon- 

 don, Messrs. R. & J. Beck received a gold 

 medal award for their microscopical and 

 other optical apparatus. The Messrs. 

 Beck have been constantly improving 

 their designs for microscopes, and now 

 offer some excellent models at very reason- 

 able prices. 



— Mr. Hinrichs, of Baltimore, has sent 

 us.forexamination.somenewpreparations 

 of bacteria, recently received from Ger- 

 many, which he is offering for sale. Among 

 them we find as especially good Bacillas 

 twina, and a preparation marked Enclo- 

 carditis iilcersa, Koch. These are from 

 Marpmann's Institute at Esens, Germany. 



— It appears from experiments of M. 

 Miquel that bacteria do not rise to great 

 heights in the air. Ten cubic metres of 

 air at heights of 2,000-4,000 metres on the 

 Alps failed to yield any bacteria. Hence 

 it is concluded that Koch's cholera mi- 

 crobes cannot pass from Italy to Switzer- 

 land unless they find their way through 

 the tunnels. 



— M. P. Francotte has written an excel- 

 lent article explaining the formation of 

 images in the microscope according to the 

 theory of Prof. Abbe. It is published in 

 the Bulletin de la Society Beige de Micro- 

 scopie, No. iv. It is an elementary expo- 

 sition of the subject, illustrated with cuts, 

 and affords a good insight into the theory. 



— At a recent meeting of the San Fran- 

 cisco Microscopical Society, Mr. William 

 Norris presented to the society a set of 

 nineteen slides, mounted by him, being 

 the first instalment of a series which, 

 when completed, is intended to be a com- 

 plete collection of all known California 

 diatoms, with a list giving the generic and 

 specific names of the diatoms found on 

 eight of the slides, from as many different 

 localities in the State, and comprising 

 both recent and fossil forms. It is the 

 first important step ever taken towards 

 the systematic collection and classification 

 of the California diatomaceae. 



The consideration ot the subject ap- 

 pointed for discussion, 'Pathogenic Ba- 

 cilli,' was then taken up. Dr. J. H. Stal- 

 lard, of San Francisco, read a carefully 

 prepared paper, giving a succinct account 

 of the present state of our knowledge on 

 the subject. He briefly reviewed the 

 gradual progress of discovery in this field 



from the time when Leeuwenhoek, the 

 father of microscopic biology, first dis- 

 cerned that minute organisms were asso- 

 ciated with putrefaction and decay, up to 

 the present day, when the magnificent 

 researches of Koch, Pasteur, Lister, and 

 others are exciting the admiration of the 

 entire scientific world. It is to M. Pasteur 

 that we owe the first observations which 

 connected an epidemic disease with the 

 presence of a parasite. He taught the 

 silk-raisers of France how to check the 

 ravages of pebrine, a disease infecting the 

 silkworm. By following his advice the 

 silk crop, which had fallen from 26,000,000 

 kilogrammes to 4,000,000, again increased 

 to its former quantity. At a still more re- 

 cent date, Lister made the discovery that 

 the exclusion of germs and the use of ap- 

 plications which prevent their growth and 

 propagation would render the practice of 

 surgery far more successfyl. By the al- 

 most universal adoption of his methods 

 many operations are now safely performed 

 which formerly resulted fatally in nearly 

 every instance. 



In April, 1882, Koch announced his dis- 

 covery of the bacillus of tubercle. These 

 bacilla are minute rod-like fungi, and are 

 readily found in the sputum of consump- 

 tives, generally free, but sometimes in 

 colonies, in the large or 'giant' cells. 

 They form spores at the temperature of 

 the body, and human sputum retains its 

 virulence after drying for considerable 

 periods. Dr. Stallard then proceeded to 

 detail the various methods of staining the 

 material containing the bacilli, and there- 

 by differentiating the latter. 



In 1883 Koch was sent to Egypt by the 

 German Government to study the etiology 

 of cholera. After a series of prolonged 

 observations he saw that a peculiar 

 comma-like form of these minute fungi 

 was invariably associated with the disease. 

 In the appearance, growth, and vital prop- 

 erties of this bacillus, many characteristics 

 were found which at once distinguished it 

 from all its congeners. No formation of 

 spores has yet been discovered. In un- 

 complicated cases of cholera, these bacilli 

 appear as pure cultivations in the intestine 

 of the patient, and their number is stated 

 by Koch to always bear a direct propor- 

 tion to the gravity of the attack. 



Although the correctness of Koch's con- 

 clusions has been denied by the members 

 of the British Cholera Commission, yet. 

 taking everything into consideration, and 

 bearing in mind the wonderfully care- 

 ful and exhaustive nature of Koch's re- 

 searches, it seems almost certain that the 



