BRIEF NOTES. 



95 



and myself have Lad pretty severe attacks, and 

 some of the others have also suffered. The last 

 man to succumb, Shadrach Ngunana, from Love- 

 dale, who has never yet had the slightest touch 

 of fever, has suffered slightly. Average health 



among the others. A greater variety and better 

 food would prevent that anremia that seems to 

 be the worst part of the fever. 



" James Stewart." 

 — Geographical Magazine. 



BEIEF NOTES. 



The Volcanoes of Iceland. — Prof. Johnstrup, 

 sent to Iceland by the Danish Government for 

 the purpose of exploring the scene of the recent 

 volcanic disturbances in that island, has made 

 his official report, a summary of which we find 

 in Nature. He first examined the volcanoes of 

 the Dyngju Mountains. These mountains are 

 not of volcanic origin. The Askja Valley, which 

 the Dyngju Mountains encircle, was evidently 

 much deeper in former times than at present: 

 repeated flows of lava have gradually filled it up. 

 Along the outer edge of the Dyngju Mountains 

 are numerous craters, which have contributed 

 most of the lava covering the plain of Odadah- 

 rann. In the neighborhood of the newly-found 

 craters the earth is covered, to the distance of 

 over a mile, with the bright-yellow pumice-stone 

 ejected during the eruption of March 29, 1875. 

 In places where the pumice-stone is several feet 

 in depth, it covers a layer of snow twenty-five 

 feet deep, and this snow has ever since been pro- 

 tected from the effects of solar heat by the feeble 

 conducting power of its covering. Not a trace 

 of a lava-stream is to be found. At present the 

 craters are to be regarded as gigantic steam-es- 

 cape tubes, the activity of which will continue 

 for an uncertain period with gradually-decreasing 

 intensity. The volcanoes in Myvatns Oraefi pre 

 sented entirely different characteristics. In the 

 centre of this barren plain, thirty-five miles long, 

 thirteen wide, a volcano suddenly appeared on 

 February 18, 1875, and four others appeared sub- 

 sequently. They emitted a mass of lava esti- 

 mated at 10,000,000,000 cubic feet. This lava 

 was basaltic and viscous when emitted, and crys- 

 tals of chloride of ammonium were found in the 

 vicinity of the craters. 



Epidemics of Trichinosis. — Between the years 

 1860 and 1875 there appeared in the kingdom of 

 Saxony 39 epidemics of trichinosis, with 1,267 

 cases of this disease and 19 deaths. From a brief 

 digest of the statistics of trichinosis published in 

 the Medical and Surgical Reporter it appears that 



only a small proportion of the cases arose from 

 eating raw pork, while one-half were produced by 

 eating smoked sausages, which, however, caused 

 only two deaths. Among 340 persons who partook 

 of well-cooked sausages eight died. The epidemic 

 appeared in 15 places once, in seven places more 

 than once, and in Dresden seven times. In most 

 instances the number of persons attacked was 

 small, the highest numbers being 209, 140, and 199, 

 and only one death resulted from the total of 548 

 cases occurring in these epidemics. In several of 

 the "epidemics" (?) the number of cases was as 

 low as from one to seven. The mean (32^) of the 

 39 epidemics was scarcely exceeded in one-fourth 

 of the places, while in three-quarters of the other 

 places the mean was not reached. In many in- 

 stances the number of cases was so small as to 

 show that a trichinized animal may be entirely 

 consumed without inducing the disease at all. It 

 is calculated that 100 trichinized pigs will give 

 rise to only four cases of the disease in man. 



Mushroom- Culture in Japan. — The Japanese 

 mode of raising mushrooms, as described by Mr. 

 Robertson, British consul, is as follows: About 

 the beginning of autumn the trunk, about five 

 or six inches in diameter, of the shu or some 

 other tree of the oak kind, is selected and cut 

 into lengths of four or five feet ; each piece is 

 then split lengthwise into four, and on the outer 

 bark slight incisions are either made at once with 

 a hatchet, or the cut logs are left till the follow 7 - 

 ing spring, and then deep wounds, seven or eight 

 inches long, are incised in them. In the former 

 case the logs are placed in a wood or grove, 

 where they can get the full benefit of the air and 

 heat; in about three years they will be tolerably 

 rotten in parts. After the more rotten parts are 

 removed, they are placed against a rack in a slant- 

 ing position, and about the middle of the ensuing 

 spring the mushrooms will come forth in abun- 

 dance. They are then gathered. The logs are, 

 however, still kept, and submitted to the follow- 

 ing process : Every morning they are put in water 



