554 



SCIENCE 



[Vol. IV., No. 



and reported for duty without serious accident or 

 illness of any of its members. 



Reports on the minerals, birds, general character 

 of the country and its inhabitants, the fur trade, etc., 

 from Engineer McLenegan, accompany the report to 

 Capt. Healy, commander of the Corwin, from which 

 the above notes are derived. The Kowak abounds in 

 salmon, pike, and white-fish, which are dried by the 

 natives. The white spruce is the largest and most 

 abundant tree. The natives are all Innuit or Eskimo ; 

 and their numbers in this region are estimated at three 

 hundred and fifty on the Nunatok, two hundred and 

 twenty-five on the Kowak, and two hundred and fifty 

 on the Selawik lakes and rivers. The coal-belt is 

 about thirty miles wide, and is probably lignitic, re- 

 sembling the small seam near Nulato, on the Yukon. 

 The 'color' of gold was obtained almost everywhere, 

 but it is doubtful if it would pay to work it. Beds 

 of a beautifully mottled serpentine, used by the 

 natives for ornaments, were found in the mountains 

 near the Kowak, as well as the so-called ' jade,' used 

 far and wide for the most costly and elegant stone 

 implements, which is perhaps the variety of pectolite 

 recently described by Clarke from specimens got at 

 Point Barrow. Seventy-seven species of birds were 

 collected, mostly of species common to the Yukon 

 region, among which the rock ptarmigan and white- 

 tailed godwit (L. uropygialis?) are noteworthy, as 

 well as the great white-billed loon (C. Adamsi). 



Commercially the most important result of the 

 expedition is the indication of a route by which 

 whalers or others, held by the ice eastward from Point 

 Barrow, might find a comparatively available way to 

 the settlements on the Yukon, hid the Colville and 

 Kowak rivers, and through the Koyukuk valley. 

 Geographically the journey of Lieut. Cantwell is the 

 most important of the past year in America; and its 

 results, taken in connection with those of Lieut. 

 Stoney, who subsequently passed over nearly the 

 same route, will give us an approximate knowledge 

 of a considerable area which has hitherto been al- 

 most a blank upon the best maps. 



THE CHOLERA BACILLUS. —KOCH'S RE- 

 PLY TO HIS CRITICS. 



The doubts that have arisen in many minds in 

 regard to the specific nature of the cholera bacillus 

 of Koch may be in some measure dispelled by the 

 latter's answers to his critics in a recent number 

 of the Deutsche medlcinische woclienschrift (No. 45, 

 1884). In it he shows the differences between the 

 cholera bacillus and that found in the mouth (Lan- 

 cet, Sept. 20, 1884), and then takes up the work of 

 Finkler and Pryor. He shows that they have not 

 obtained pure cultures (this from specimens of their 

 own); that their bacillus is larger and thicker, more 

 rapid in growth, and very different in 'culture-form.' 

 In examinations of three cases of ) cholera nostras,' 

 he failed to find the 'comma bacillus.' Koch has 

 also succeeded in producing cholera by the inocula- 



tion of one one-hundredth of a drop of a solution 

 of a pure culture. This produced death in rabbits 

 and guinea-pigs in from one and a half to three days, 

 when placed in the duodenum. The appearances 

 X>ost mortem were those of the human subject in 

 death from Asiatic cholera. 



In addition to this, we have the confirmatory evi- 

 dence of E. van Ermengen in a communication to 

 the Belgian microscopical society, Oct. 20, 1884 

 [Lancet, Nov. 29, 1884). This observer found the 

 comma bacillus in the intestinal fluids of eight au- 

 topsies and thirty-four examinations of stools. He 

 considers that its peculiar-shaped, chain-like groups 

 and occasional wavy filaments distinguish it com- 

 pletely from other bacteria. He finds that it is more 

 or less abundant, according to the stage of the dis- 

 ease; and in two cases (foudroyant) they were pres- 

 ent almost as in a pure culture. They disappear 

 during reaction. 



Premonitory diarrhoea was not investigated for the 

 presence of the organism, for lack of time. In cases 

 of algide cholera, where no bacilli were found in the 

 stools, culture of the most minute portion produced 

 enormous numbers of the organism within twenty- 

 four hours. He considers that the presence of the 

 organism is diagnostic of cholera, and that the method 

 of microscopic examination in conjunction with cul- 

 tures should be adopted in all doubtful cases. By 

 thus settling the diagnosis early, efficient prophylaxis 

 against the spread of the disease may be established. 

 He found no spores, and considers their absence 

 probably established by the want of resistance to 

 drying of this organism. He finds precisely the same 

 differences between the cholera bacillus and those of 

 Lewis and of Finkler and Pryor, and exactly the same 

 objections to the latter's work, as does Koch (loc. 

 cit.). He, as well as Koch, succeeded in producing 

 cholera by inoculation of one drop of a culture, ex- 

 tending over four days (this in dogs, guinea-pigs, 

 and rabbits). The cadaveric appearances were those 

 of cholera; and the intestinal fluids contained many 

 comma bacilli, from which further cultures were 

 made. He thinks that the pathogenic action of these 

 bacteria is very likely due to some product of their 

 growth in the material in which they are sown, and 

 closes his communication by advising that physicians 

 generally should be instructed in the methods of 

 microscopic search for these organisms in order to 

 the early determination of the existence of the dis- 

 ease, and all that that implies. This is a recommen- 

 dation which might be made in this country, and 

 adopted with much benefit to the community at 

 large. 



Such observations as these furnish strong evidence 

 that the world is again indebted to Koch for his 

 labors in the investigation of disease, and that the 

 links connecting his cholera bacillus with cholera as 

 its specific cause are being forged into a complete 

 chain of evidence. 



In regard to the organism itself, we have received 

 within a day or two a slide containing masses of 

 bacilli from a pure culture. The preparation is a 

 very beautiful one ; and its authenticity is undoubt- 



