MISCELLANY. 



j6\ 



that temperature is not the only condition 

 modifying vegetal growth at varying alti- 

 tudes, but that varying degrees of atmos- 

 pheric pressure have also a controlling in- 

 fluence in this respect. Some grains of 

 wheat were sown in bell-glasses with all the 

 conditions identical, save that the contents 

 of one glass were subjected to the normal 

 pressure of the atmosphere, those of an- 

 other to two-thirds the ordinary atmos- 

 pheric pressure, and those of a third to 

 one third the ordinary atmospheric pressure. 

 The first grains sent forth shoots 20 centi- 

 metres (7 inches) long, the second 5 inches, 

 and the third did not come up at all. Again, 

 with a pressure of 5 atmospheres, the plants 

 did not come up, the radicles only having 

 been sent out, and on opening the vase a 

 strong alcoholic odcr was perceived, in 

 place of the ordinary acetic odor of putre- 

 fying wheat. After a few days a mould 

 made its appearance. 



Electric Detonators for exploding Mines. 



Two new electric detonators, for explod- 

 ing mines, one for land and the other for 

 marine service, have been introduced in 

 England. The former consists of a tin 

 tube filled with fulminating mercury, and 

 having a head of beech-wood. The electric 

 wires run through this head, being insulated 

 by gutta-percha, and their extremities held 

 apart. In the space between the ends of 

 the wires, and in contact with the fulminat- 

 ing mercury, is loosely packed a little gun- 

 cotton, which is ignited by an electric cur- 

 rent. The marine detonator has also a 

 tube of tin filled with fulminating mercury, 

 as also a beech-wood head. From tip to 

 tip of the wires extends a platinum wire -ft- 

 inch long, and 0.003 inch thick, in a bed 

 of loose gun-cotton. The electric current 

 heats the platinum, thus igniting the gun- 

 cotton and exploding the fulminant, which 

 in turn explodes the powder. 



Development of Yibrio-Lifc. In the 



course of his very interesting experiments 

 on protoplasmic life, Dr. Grace Calvert shows 

 that a solution of albumen from a new-laid 

 egg, in pure distilled water, does not develop 

 protoplasmic life, when the atmosphere is 

 shut out. If, however, it be exposed to 

 the atmosphere for from 15 to 45 minutes, 



minute globular bodies will appear, which 

 have an independent motion. The time re- 

 quired for these bodies to develop is pro- 

 portioned to the surface exposed, as was 

 shown by Dr. Calvert, who experimented 

 with two portions of albumen, 400 grains 

 each, one in a test-tube of three-fourths 

 inch diameter, and the other in a test-glass 

 showing a surface of liquid two inches in 

 diameter to the atmosphere. In the tube, 

 vibrios appeared after twelve days, but in 

 the glass after five. With undistilled wa- 

 ter, they appeared in the test-tube within 

 24 hours. Further, M. Pasteur having 

 shown oxygen to be necessary to the life 

 of the mucedines, Dr. Calvert shows that 

 it is no less necessary to the existence of 

 vibrios. To confirm this, he put into each 

 of five glass bulbs a solution of albumen in 

 water, the first being left in contact with 

 the atmosphere 24 hours, and the ends of 

 the tube then hermetically sealed about two 

 inches on each side of the bulb. The other 

 tubes were similarly closed, after passing 

 oxygen, hydrogen, nitrogen, and carbonic 

 acid, over the solutions. The tubes re- 

 mained closed for 27 days, during which 

 period the albumen in contact with oxygen 

 was seen speedily to become turbid, and 

 then that in contact with air, while the oth- 

 er three remained clear. The tubes were 

 then broken, and it was found that those 

 containing oxygen and common air held a 

 large amount of vibrio-life, while those 

 containing nitrogen, carbonic acid, and hy- 

 drogen, held but very small quantities ; hy- 

 drogen least of all. Thus it was proved 

 that oxygen is an essential element to the 

 production of putrefactive vibrios. The 

 transition from globular protoplasms, or 

 monads, as he calls them, into vibrios, and 

 their ultimate transformation into micro- 

 zyma, is then described by Dr. Calvert. " A 

 few hours after impregnation," says he, 

 " the monads appear in the albumen, hav- 

 ing a diameter of about ttzsWu of an inch, 

 and appear to form masses. Next, some 

 of the monads are lengthened into vibrios, 

 which have an independent motion, though 

 still attached to the mass. As this motion 

 prevails in this or in that direction, the 

 mass is moved over the microscope-field. 

 At last it is broken up, and soon each indi- 

 vidual vibrio is seen rolling or swimmin'* 



