February 26, 1892.] 



SCIENCE. 



123 



The bacteria showed the following peculiarities: — 

 1. In fresh cases the bacteria are found in large masses in 

 the mucus, that is, in the inner of the leucocytes; they form 

 a thick layer on the surface of the inflamed mucous mem- 

 brane, and press into the superficial lymph-spaces and often 

 also into the inner organs. 



3. They form very fine, generally pointed, diplobacteria, 

 or short rods, with a diameter of 0.2yU, often making chains. 

 One recognizes ia the inner of the same chromatic granules; 

 these appear to be surrounded by a light zone, and they are 

 without motion. With aniline colors they stain feebly, in 

 single cases better, and are faint, or do not stain at all (except 

 the chromatic granules), with Gram's jnethod. In older 

 cases and cultures, as in the inner of the leucocytes, the 

 bacterium is found in a state of granular disintegration, fre- 

 quently lessened in size or swollen so that the thickness of 

 the individual bacteria can vary between 0.1 and 0.3 yu. 

 The thickness also varies according to the coloring matter 

 employed. 



3. The bacteria can be cultivated in many cases, especially 

 in glycerine. There are formed here, especially deep in the 

 nutriejit medium, very small rod-like colonies. 



4. The bacterium is pathological for rabbits, since in some 

 cases its introduction into healthy nasal cavities causes a 

 sort of sepsis, pneumonia, and death of the animal. 



From Babes's investigations it appears that white mice are 

 not always immune against greater quantities of the culture 

 or the products of the disease, and that they can die. 



As there is now no special diflBculty in recognizing and 

 cultivating the very small bacteria in cover-glass prepara- 

 tions, it is to be hoped that they may be made valuable in 

 diagnosis, and that a way for preventing and subduing the 

 disease may be experimentally investigated. 



Georgetown Medical School. A. MacDoNALD. 



them before the inner scales have fallen — as they are opening. 

 Do not be satisfied with mediocrity, but strive to have everything 

 neat and complete. "W. J. Beal. 



Agricultural College, Ingham Co., MIoh., Feb. 23. 



LETTERS TO THE EDITOR. 



Making an Herbarinm or Preserving Plants. 



This is the tioae of year when botanists are making plans for 

 the summer campaign. I am not going through the subject by 

 going into details, as Science has recently noticed sevei-al small 

 manuals which treat fully of the subject. I wish to emphasize a 

 few points which have received too little attention. I am some- 

 what familiar with the collecting done by the older botanists of 

 this country, and with some in other countries. 



We have a great advantage in many ways over the older col- 

 lectors. We are learning all the time from each other. We are 

 going deeper and deeper into the study of plants. 



Almost everyone who preserves specimens, on the start hoards 

 up a lot of worthless trash — of snips, tops, and mere fragments. 

 Don't do it, but study the subject well from every side. I speak 

 now more particularly with reference to grasses ; but the following 

 statement, I feel sure, will apply with almost equal force to most 

 families of plants. This is the statenlent which I beUeve to be 

 true, with very few exceptions: — 



All truly good herbarium specimens have been made within the 

 past twenty years, and a very large proportion of those prepared 

 during the last twenty years are far from good. It is no injustice 

 to others to say that, so far as I know, C. G. Pringle of Vermont, 

 by his fastidiousness in this matter, started a reform which seems 

 to be rapidly spreading. We should have an abundance of mate- 

 rial, lower leaves, flowers, fruit, and root-stalks, if there are any, 

 and little packages of nuts, flowers, and seeds on the sheet for 

 study. Some years ago I spoke of the importance of preserving 

 seedlings of many of our plants. This is a good time to refer to 

 this part of the subject, since Mrs. Kellerman has illustrated the 

 seedling blackberry. Turn to page ninety-four and study it. 

 Go to raising seedlings, or pick them up wherever they can be 

 .found. Lookout, too, for buds of trees and shrubs, and collect 



The Barn Owl a Winter Resident in Ohio. 



That the bam owl, Strix pratincola, is, at least, a rare winter 

 resident of central Ohio can no longer be questioned. A few days 

 since two individuals were found in the hollow trunk of a syca- 

 more tree at Utica, Licking County. One of them was killed by 

 the fall of the tree; this I have not seen. The other was taken 

 alive, and I had the satisfaction of seeing it last week in the pos- 

 session of Mr. Newkirk of Newark, O. There is no doubt as to 

 its identity, nor can I think there is any regarding the stated time 

 and place of capture. 



There are but few recorded instances of its occurrence in the 

 State, and none of the dates at hand are in winter. Dr. J. M. 

 Wheaton, in " Reports on the Birds of Ohio," says, " Rare visitor. 

 Mr. Oliver Davie of this city [Columbus] has a specimen . . . 

 killed in this vicinity Nov. 3, 1878. The dates of captures [Cir- 

 cleville, summer, 1873; Columbus, November, 1878; near Cincin- 

 nati, April, 1880] indicate that it is, at least, a summer resident 

 of the State." It would seem that it is a permanent resident; in 

 all probability rearing its young in central Ohio. 



D. S. Kellicott. 

 Ohio State University, Columhus, Feb. 17. 



A Magnetic Cane. 



Capt. D. p. Sanford of this city owns a walking-stick that 

 possesses magnetic properties, but how it came by them he is un- 

 able to explain. Several years ago he purchased a strong, heavy 

 cane, having for its central portim a rod of excellent quality of 

 steel, extending throughout its entire length. At the lower end 

 it is about the thickness of the ordinary lead pencil; at the 

 top nearly three-quarters of an inch in diameter. Its outer part 

 is composed of leather, which, having been cut into rings, was 

 forced, one ring upon another, till solid from end to end. This 

 was rounded, smoothed and polished, and varnished. The cane 

 was finished, first, by enclosing the lower end with a steel ferrule 

 through which the central steel rod projected half an inch ; sec- 

 ond, by covering the upper end of the cane with a circular copper 

 plate over an inch in diameter, and about one-sixteenth of an 

 inch in thickness. 



The cane was never near a magnet to its owner's knowledge ; 

 but recently he has noticed its magnetic property, which, in his 

 belief, is gi-owing stronger. Now, what causes this ? 



The water-tight non-conducting covering insulates the rod per- 

 fectly, except at the lower end, where, as a matter of course, it 

 constantly comes in contact with the earth. The upper part, cov- 

 ered with the copper plate, is held in the warm and moist hand 

 for hours at a time. Now, will the conditions of insulation, two 

 metals, moisture of earth and hand, and difference in temperature 

 between the two ends, account for the exhibition of magnetic 

 properties ? Will some one offer an explanation ? 



A. H. Beals. 



MilledgeviUe, Ga., Feb. 20. 



[If the writer of the above will take any steel rod and give it 

 a number of raps while held in a more or less vertical position he 

 will find that it will become magnetic. — Ed.] 



AMONG THE PUBLISHERS. 



The question of " Speed in Locomotives," which for a time 

 has superseded in popular interest the luxuries of railroad travel, 

 will be discussed in the March Scribver by a notable group of 

 railway authorities. M. N. Korney, editor of The Railroad and 

 Engineering Journal, will consider the question of "The Limita- 

 tions of Fast Running;" Theodore N. Ely, General Superinten- 

 dent Motive Power, Pennsylvania Railroad, will treat of "Train 

 Speed as a Question of Transportation ; " H. Walter Webb, Third 

 Vice-President of the New York Central, will describe "A Prac- 

 tical Experiment" — the running of the Empire State express. 

 The views of three sueh authorities, presented in a popular way 

 in one number, give for the first time an adequate knowledge to 



