I'ilVSlUUMiV. 



885 



half of this time being spent in raising 

 ami half in lowering tin- weight. For the first 

 lew days fatigue of the part was felt, ami in- 

 deed li.r fourteen days m> marked advance was 

 made. On the fourteenth day the exercise lasted 

 I'onds. I-Yoiu this time on there was a 

 gradual rise of tin- curve until the forty-first 

 day, when, though there were many oscillations, 

 I lie rise U'came very rapid. The oscillations 

 \\ere attributed to the conflict of the two in II u- 

 ences, fatigue and exercise. The greatest time 

 tliat the work was continued was 092 seconds, 

 and this by excessive disturbance of respiration 

 and circulation, the whole system, as it seemed, 

 revolt in-,' against the work. Hence, Fechner 

 concluded that the limit of the effect of exercise 

 upon the muscles is not set by the muscles, l>ut 

 by the constitution. He suggests that by well- 

 regulated exercise the constitution might be 

 altered, and inured to bear fatigue. 



In a great military march on cycles, executed 

 by the Twenty-sixth Middlesex Cycling Corps, 

 England, from Hitchin to Peterborough and 

 back, a distance of 100 miles and 200 yards was 

 covered in ten hours and fifty-seven minutes. All 

 precautions were taken to avoid excessive pres- 

 sure and to provide refreshment at convenient 

 intervals; and although the weather and part 

 of the ground were unfavorable, the men came 

 out of the exercise without fatigue. The most 

 interesting feature of the story, as told in the 

 " Lancet,' is that Major Knox Holmes, who was 

 closing his eighty-third year, mounted on a tan- 

 dem with a rider eighteen years of age, accom- 

 panied the corps, and arrived at the termination 

 of the expedition five minutes in advance of the 

 rest. He was a little distressed on dismounting 

 from too hard riding in the last few miles, but 

 soon threw off his fatigue and joined his com- 



Sanions at dinner with thorough zest. His con- 

 ition is described as physiologically peculiar. 

 In twelve weeks' new training he developed 

 muscle in the most striking manner in the ex- 

 ternal and the internal vasti, the rectus, and the 

 muscles which form the calf of the leg. It has 

 become so entirely a part of physiological doc- 

 trine, the writer says, that after three-score 

 years and ten there is no new development of 

 muscle, that if he had not seen with his own 

 eyes, as he had, this actual development in one 

 whose age exceeded by thirteen years the tradi- 

 tional span of human life, he should have doubted 

 the possibility of its occurrence. 



Vegetable Physiology. From experiments 

 made in the Botanical Gardens at Buitenzorg, 

 Java, Herr HalieHandt draws an argument 

 against the view that the transpiration current is 

 of first importance in the nutrition of land plants. 

 The tropical plants showed transpiration greatly 

 inferior in amount to that of European plants, 

 yet they had luxuriant vegetal ion. and were able 

 to convey nutritive salts to Their highest parts. 

 It is curious that, in spite of the great humidity 

 of the air and the large amount of water in the 

 ground, these plants often possess guards against 

 too great transpiration, such as thick, cuticular- 

 ized epidermis, deeply sunk stomata, and espe- 

 cially tissues adapted for storage^f water. And 

 the reason can not lie, as sometimes at the const, 

 in the presence of salt in the ground. Herr 

 Haberlandt finds an explanation in the fact that 



while the total transpiration i comparatively 

 small, the hot sunny forcmx.iiH may o< . 

 large cvaporat ion. Tlie transpiration in a fore- 

 noon hour was, in general, from 4 to \2 times 

 that of an afternoon hour; sometimes as much 

 as :.'<) or :{() times. The forenoon hours are by 

 far the most favorable to assimilation, and it is 

 most important to the plant that itsturgi 

 be not then too much depressed, an end accom- 

 plished through those water reservoirs. 



From recent researches on transference of ma- 

 terial in plants, for example, by transference of 

 starch in the potato, Herr Brasse is led to pre- 

 sent the following view of what goes on : The as- 

 similation of carbon in the sun's rays is mani- 

 fested directly in deposition of starch in the 

 chlorophyll grains. Through action of diastase 

 in the leaves and at a temperature lower than 

 that of its formation this starch is changed into 

 reducing sugar, which spreads by diffusion from 

 its place of formation to all the tissues of the 

 plant. In certain parts, and especially in the 

 tubers, the sugar is continuously transformed. 

 The tubers, with regard to dissociation, act like 

 the cold wall in vaporization of a volatile liquid 

 in an inclosed space. The sugar content of all 

 cells of the plant seeks to enter into equilibrium 

 with that of the cells of the tubers in which the 

 content is less, because a change of sugar into 

 starch takes place, and the coefficient of this 

 change is here less than that of the converse 

 change in the leaf, the temperature of the tuber 

 being less. Owing to this inequality, there is a 

 transference of starch from the leaf into the 

 tuber in which it passes through the intermediate 

 stage of sugar. In a similar way Herr Brasse 

 would explain the transference of nitrogenous 

 and mineral plant materials and their storage in 

 special organs. 



Some interesting researches into the atmos- 

 pheric sources of nitrogen as plant food have 

 been made in the Agricultural and Veterinary 

 School at Copenhagen. The proportions of nitric 

 acid and ammonia in the rain water collected in 

 the pluviometers of the experimental fields was 

 measured for each month of the years 1880-'85. 

 The quantity of ammoniacal nitrogen was rela- 

 tively greater in winter and in cold springs, it 

 oscillating in winter rains between 1*05 and 7^98 

 milligrammes per litre, and in summer rains 

 from - 7 to T5 milligramme. Observations 

 made at other stations were confirmed, accord- 

 ing to which summer rains are not always ;.s 

 compared with those of other seasons, richest in 

 nitric acid. In two years only out of the five 

 years of experiment did the summer rain contain 

 the most nitric acid. The quantity of ammonia 

 much exceeded that of nitric acid ; in one of the 

 five years it was 84 times as much; yet in July. 

 1888, and August, September, and November, 

 1884, nitric acid was dominant. In total nitro- 

 gen, the summer rains those of June, July, and 

 August except in lb83-'84, furnished less rela- 

 tively t lian those of other seasons. From 14 to 

 82 per cent, of the year's nitrogen appears to 

 have been furnished" during the three months 

 proper of vegetation (May, June, and July). The 

 author remarks that the figures he gives are max- 

 ima, the investigations having been made near a 

 large city. The importance to plants of nitrog- 

 enous combinations included in ruin water should 



