August io, 1888.] 



SCIENCE. 



7» 



of a sheep not rendered immune against the disease ; the blood of 

 the rabbit killed off many bacteria, more, in fact, than the blood of 

 sheep, sheep being, as is well known, much more susceptible to the 

 disease than rabbits. On the other hand, the blood of a mouse had 

 no visible effect on bacilli, in the latter case the animal being ex- 

 tremely sensitive to the disease. That the animal cells do not play 

 any thing like the active role frequently assigned to them (' Phago- 

 cyte' theory of Metschnikoff and followers) is pretty clearly shown, 

 it being found that the bacteria die off quite independently of the 

 cells or leucocyte in and out of the body. Of saprophytic bacteria 

 some forms are found more sensitive than others. Fluids taken 

 from various individuals of the same species vary to some extent 

 in their germicidal qualities. To give an idea of the intensity of 

 this action, a case or two might be cited. Five drops of defibri- 

 nated rabbit's blood, placed at 37-38° C, reduces the number of 

 anthrax bacilli inoculated into it from about 15,000 to 5 at the end 

 of an hour; in another case, from about 90,000 to o at the end of 

 four and five hours. Rabbit humor aqueus (contains little or no 

 cellular elements) reduces the number of anthrax bacilli inoculated 

 into it from about 10,000 to i, and m another case to o, at the end 

 of two hours; in fresh human pleuritic exudate, 230 anthrax bacilli 

 are entirely killed off after one and two hours. Human saliva was 

 also found to kill off large numbers of bacteria in a short time. The 

 encouraging of bleeding, and the sucking of a wound in certain 

 . cases, may not be bad treatment, after all, when we consider the re- 

 sult of the above experimental research. 



— Prof. F. W. Clarke describes, in a contribution to the Ainerz- 

 can yournal of Sciettce, the results of a series of investigations into 

 the manner of formation of nickel silicates. About the year 1881 

 extensive deposits of this ore were found in Douglas County, Ore- 

 gon. They lie near the surface in beds from four to thirty feet 

 thick, and no second beds have been found underlying the first. 

 Most of the samples obtained are intermixed with oxides of iron 

 and with quartz, and are seamed with chalcedony. All of them 

 are undoubtedly products of alteration, which is true of similar 

 samples procured from the deposits in New Caledonia and in 

 North Carolina. The country rock in these three localities is al- 

 most identical, consisting of a greenish rock, composed of olivine 

 partially altered into serpentine, and having considerable quantities 

 of enstatite mingled with it. The only noticeable difference in oc- 

 currence was that chromic iron, an almost universal associate of 

 the nickel silicates, is absent in Oregon. Analyses of these various 

 ores show great dissimilarity in composition, even between speci- 

 mens from the same deposit. The percentage of nickel oxide va- 

 ries from 0.24 to 45.15 per cent, but magnesia is present sometimes 

 to the extent of 22 per cent, and this would lead to suspicions that 

 alteration in the olivine, which is a silicate of magnesia and iron, 

 had something to do with it. Actual analyses of the olivine rock 

 confirmed at least the existence of nickel in it, varying in quantity 

 from o.io to 0.26 per cent. Mr. Clarke quotes Dr. T. Sterr)' Hunt 

 as saying that nickel is almost always present in small quantities in 

 olivine, and rarely absent from the serpentines, steatites (soap- 

 stones), and allied minerals of the Quebec group. As a result of 

 these investigations, Mr. Clarke concludes that the olivine, which 

 always occurs with these ores, and which so readily alters, has 

 supplied the nickel which is found as silicate, not only in Oregon, 

 but at other localities so far obsen.-ed. 



— Those who are obliged frequently to refer to German books 

 are especially interested in the movement to introduce the Roman 

 in place of the Gothic alphabet. Since 1866 the society which is 

 agitating this matter has nearly doubled in numbers. On its lists 

 are now over 4.436 names, including members of all professions, 

 teachers, physicians, booksellers, and merchants. In 1 886, out of 

 6,913 books on artistic, scientific, mercantile, and industrial sub- 

 jects, 5,316 were printed with the Roman letters. 



— J. N. Emra, late lieutenant Royal Marines, has issued a little 

 book (London, Kegan Paul, Trench, & Co.; New York, the author) 

 descriptive of the cruising of H. M.S. ' Royal Oak' in the waters of 

 the Mediterranean. The author calls his book ' The Centre of the 

 Central Sea,' and devotes himself to Malta. Sicily, and an ascent of 

 Mount Etna by some of the officers, describing the phenomena of 

 the volcano as he saw them. 



LETTERS TO THE EDITOR. 

 Our Native Birds. 



An editorial paragraph in your issue of Aug. 3 assumes that our 

 native birds have this season been unusually abundant ; the as- 

 sumption being based, so far as appears, upon statements " in the 

 New York papers " and upon " information from Illinois," where 

 " the oldest inhabitant does not remember to have seen so many 

 and such a variety of birds." This is good news, —almost too- 

 good, — and, for one, I could wish it better vouched for. 



In this part of the country, according to my own observations 

 (and I have never been more in the field than this yearj, there has 

 been no such state of things, either during the migratory move- 

 ment or since. There are days in April, and again in May, as 

 every ornithologist knows, when the woods and fields are fairly 

 alive with migrants. That was true this year, but no truer than it 

 is every year. 



This piece of negative evidence proves nothing, of course ; and I 

 should hardly have thought it worth offering had even one orni- 

 thologist been named as authority for the fact in question. But in 

 such matters mere newspaper reports seem to me of small account, 

 while my acquaintance with the oldest inhabitant of Massachusetts 

 does not incline me to put unqualified faith in the opinions of the 

 oldest inhabitant of Illinois as to the comparative abundance either 

 of individual birds or of species. 



In short, I am suspicious of the testimony, and therefore of the- 

 facts ; but if the facts can be established, then I join you in hoping 

 that the editors of the Auk will favor us with an explanation. As 

 for the one already suggested (by "the New York papers," as I 

 infer), it is plainly insufficient, in more ways than one. If the Eng- 

 lish sparrows were largely or wholly destroyed, it would be an- 

 occasion for thankfulness (I speak for myself) ; but the supposition 

 that their destruction in March would be followed by a great in- 

 crease in the number of our native birds within two or three 

 months seems to me very unreasonable. Bradford Torrey. 



Melrose Highlands, Mass., Aug. 5. 



Referring to the editorial note in your issue of Aug. 3, the 

 failure of ornithological journals to comment on the apparent in- 

 crease in bird-life during the present season is perhaps an evidence 

 that such comment is uncalled for. It is true that during the 

 vernal migration there was at one time an unusually hea\7 ' wave " 

 of migrants, the north-bound stream being held in check for several 

 successive days by unfavorable weather. This obstacle t)eing re- 

 moved, and pleasant weather succeeding, there resulted an over- 

 flow of past-due birds, which flooded the country in such accumu- 

 lated numbers as to excite remark by the most unobservant, as. 

 the numerous articles in the daily press of that period will testify. 



The migration over, and our avifauna being sifted down to- 

 purely summer resident species, a comparison of the number pres- 

 ent with those of preceding years yields, so far as my own obser- 

 vations go, remarkably similar results. To illustrate : I find 

 recorded in my note-book on Aug. 5, 1886, observations on thirty- 

 one species observed during a morning's walk. Of these, eight 

 are given as * common," three as ' tolerably common,' and the 

 balance as ' two or three." ' three or four," etc. ; and on Aug. 7, 

 I S87. thirty-five species, of which ten are recorded as 'common," 

 ten as ' tolerably common,' and the balance as in the preceding; 

 while on Aug. 5, 1888, the result of a walk over exactly the same 

 district was thirty-three species, ten being ' common,' three ' toler- 

 ably common,' and the balance as before. 



Local observations of this nature, however, can do little more- 

 than assist in making a whole, and only from a mass of com- 

 parative data can we assert that the number of individuals compos- 

 ing our avifauna during the present year is greater or less than in 

 years preceding. Frank M. Chapman. 



Englcwood. N.J., .\ug. s. 



The Relation between the Sourness of Certain Acid Solutions 

 and the Amount of Acid contained. 

 The experiments recorded below are a continuation of some 

 studies on the delicacy of the special senses, by Prof. E. L. Nichols, 

 and myself and Mr. E. C. Franklin and myself, the results of 

 which have appeared in ScUna. Xature. the Proceedings of the 

 Kansas Academy of Science, and elsewhere. By these investiga- 



