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THE POPULAR SCIENCE MONTHLY 



as now published by Mr. Thomson in the 

 Chemical News, it appears that eggs, when 

 the shells are intact, can only be decom- 

 posed by one, two, or all of three different 

 agencies. The first of these agencies is the 

 putrid cell. This may be developed in the 

 egg, however effectually the shell is pro- 

 tected against spores from without, or the 

 diffusion of gases ; it is generated from the 

 yelk. Certain gases have the effect of re- 

 tarding or preventing its growth, as car- 

 bonic dioxide and coal-gas, but it is pro- 

 moted by oxygen. One egg, which had for 

 118 days remained in an atmosphere of oxy- 

 gen, was found to be decomposed entirely 

 by " putrid cell ; " the yelk had expanded, 

 and was thoroughly mixed up with the 

 white, and the contents emitted a putrid 

 smell. The atmosphere, once pure oxygen, 

 on analysis showed only a fraction of one 

 per cent, of that gas, while the amount of 

 carbonic dioxide was 95 per cent. 



The second agency in decomposition is 

 a vibrio, which in all cases comes from 

 without, and never exists originally in the 

 egg. Whole eggs that remain dry, exposed 

 to the atmosphere for any length of time, 

 are never attacked by this animalcule ; but, 

 if the outside of the shell becomes moist, 

 the vibrios floating in the atmosphere fall 

 on it and develop in the contents. The 

 third agency is a fungus, the Penicilium 

 glaucum, which exists suspended in the at- 

 mosphere. If whole eggs are placed in a 

 constant draught of air, but few will be at- 

 tacked by this fungus ; but, if they are left 

 in a stagnant atmosphere, the floating spores 

 will settle on the shell, and send their long 

 fibres through it into the contents. This 

 fungus cannot grow in an atmosphere of 

 carbonic dioxide, but in oxygen its growth 

 is most luxuriant. In some cases of decom- 

 position by the penicilium the egg was found 

 to appear as if it had been perfectly coagu- 

 lated by boiling. The filaments of the fun- 

 gus branch about in immense numbers in all 

 directions, twisting and twining into each 

 other among the contents. 



Experiments on the Living Unman 

 Brain. Some experiments, made by Dr. 

 Bartholow, of Cincinnati, on the living hu- 

 man brain, having drawn upon him the 

 sharp censure of sundry professional jour- 



nals, he has offered an explanation of his 

 conduct in the British Medical Journal. 

 " The person on whose brain the experi- 

 ments were made was," he writes, " hope- 

 lessly diseased with a rodent ulcer, which 

 had already invaded the dura mater ; life 

 could not have lasted much longer in any 

 case. The patient herself consented to have 

 the experiment made. The experiment con- 

 sisted in applying electricity to the brain, 

 as in Terrier's researches, and it was be- 

 lieved that fine insulated needles could be 

 introduced without injury, for the following 

 reasons : The brain has been successfully 

 incised to discharge pus. Portions of the 

 brain have been lost without fatal injury to 

 the patient. Then, the faradic current was 

 used, which has no electrolytic action. In 

 the present case it was the ulcer, not the 

 puncture of the needles, that caused death." 

 Dr. Bartholow concludes his letter as fol- 

 lows : "Notwithstanding my sanguine ex- 

 pectations, based on the facts above stated, 

 that small insulated needle-electrodes could 

 be introduced without injury into the cere- 

 bral substance, I now know that I was mis- 

 taken. To repeat such experiments with 

 the knowledge we now have, that injury 

 will be done by them, would be in the high- 

 est degree criminal. I can only now ex- 

 press my regret that facts which I hoped 

 would further, in some slight degree, the 

 progress of knowledge, were obtained at 

 the expense of some injury to the patient." 



The Struggle for Existence. Mr. Buck- 

 land recently fought a pitched battle in the 

 Round Pond, Kensington Gardens, with the 

 innumerable hosts of a crustacean parasite 

 that was destroying the fishes. Having 

 learned that there was something wrong at 

 the pond, Mr. Buckland went there to make 

 a reconnoissance, and found, at one point, 

 some little distance from the bank, a dense 

 " cloud of fish." Having waded into the 

 midst of them, he discovered that the sup- 

 ply-pipe, through which fresh water was 

 admitted to the pond, was nearly choked 

 up. The fish wanted fresh water, evident- 

 ly. He took up with a landing-net one or 

 two of those that were most sickly, and 

 found them literally covered with parasites. 

 Various means were tried for removing the 

 parasites, the most expeditious way being 



