RABDWICKE'S SCIENCE-GOSSIP. 



211 



MICROSCOPY. 



The Origin of Life.— Dr. Crace Calvert read 

 a paper " Ou the Action of Heat on Germ Life." 

 The paper described a series of experiments made 

 by the author for the purpose of determining the 

 effect of heat on living organisms. lie took a 

 solution of white of egg full of microscopic life, 

 and a solution of gelatine full of microscopic life, as 

 also solutions of sugar and hay. These solutions 

 were put into little tubes, and submitted to tem- 

 peratures of 100', 200°, 300', 400', and 500' Eahr. 

 It was found that at 100' the living organisms were 

 not at all affected ; at 200' they were not affected ; at 

 300' they were still alive— three or four vibrios in 

 each field; and it was only at 400' that life dis- 

 appeared. The same solutions were then put on 

 little slips of glass, dried, some in the air and some 

 at a temperature of 212', and introduced into tubes. 

 As before, it was only at 400' that life disappeared. 

 By another experiment it appeared that in a fluid 

 where life had been destroyed by heating to 400', 

 no life was subsequently developed, whereas in one 

 which had been heated to some of the lower tem- 

 peratures, such development took place. If, said 

 Dr. Calvert, there was such a thing as spontaneous 

 generation, he could not understand why there 

 should not have been life reproduced in his tubes 

 which had been heated to 400'; whilst a little life 

 was reproduced in one heated to 300', and more in 

 one heated to 200'. It appeared to him that 

 medical men would do well to consider the tempe- 

 rature at which life was destroyed. Admitting that 

 contagious disease was due to the introduction into 

 the system of a germ of some kind, either vegetable 

 or animal, so far as his experiments went, a tempe- 

 rature of 400' was necessary to destroy such germs 

 on clothing to which they might have become 

 attached. 



Another, paper by Dr. Calvert, "On Proto- 

 plastic Life," was next read. If, said the Doctor, 

 the white of a fresh egg was taken and mixed with 

 water, and examined under the microscope, not the 

 slightest life was to be seen, but at the end of 

 twenty minutes or half an hour, plenty of life might 

 be discovered. In such experiments a fluid must 

 be employed, and whatever fluid was employed, if 

 examined under the microscope, it showed life. 

 Common distilled water, if kept for two or three 

 days, showed life ; but after many failures, he dis- 

 covered an apparatus by means of which he had 

 been enabled to get distilled water which would 

 keep free from life for three months. Having thus 

 got a pure medium without life, the question was 

 whether he could generate life in it. He intro- 

 duced distilled water into twelve tubes, and left 

 them exposed to the air for twenty four hours. It 



was in winter; in the summer he should have left 

 them for ten minutes. Another series of tubes 

 were placed near putrid meat, and then closed. 

 Life appeared in twenty-four days in the tubes 

 containing distilled water, which had been exposed 

 to the air, but a portion of the same water which had 

 not been exposed to the air showed no life. The 

 tubes which had been placed near putrid meat 

 showed life in eight days. The distilled water was 

 thus impregnated with more life by being placed 

 near a source of putridity. Up to this point he 

 had been using hydrogen to wash his apparatus. 

 He replaced the hydrogen by oxygen, and found 

 that by using water saturated with oxygen he pro- 

 duced life in three or four days instead of eight 

 days. Then taking water into which a little 

 albumen had been allowed to run without being 

 exposed to the air, he found life developed in 

 two days. The general result of the experiments 

 was that life was produced if the fluid under 

 examination was left exposed to the air for a 

 very short period. If perfectly sweet eggs were 

 covered with varnish they would keep for eighteen 

 months, while if not so covered they would not 

 keep as many weeks. But if there was such a 

 thing as spontaneous generation, why should not 

 the egg covered with varnish decompose as soon as 

 the other ? 



The new Elephant Parasite (Idolocoris ele- 

 phant is, Walker). — In reply to a notice in the last 

 Science- Gossip, by Mr. T. G. Denny, I beg to 

 state that the then unique specimen of this insect 

 was placed in my hands, two years ago, by Mr. T. 

 Curties, E.B.M.S., and I at once declared to that 

 gentleman my belief that it was " an entirely new 

 form of parasite." This fact disposes of the asser- 

 tion of priority of discovery or possession. That the 

 species was not published without due care and dis- 

 crimination is proved by its not appearing until last 

 June. In .corroboration of my opinion as to the 

 novelty of this parasite, I have not only the autho- 

 rity of Mr. P. Walker, P.L.S., but now also that of 

 the late Mr. Denny, who, as is stated by Mr. T. G. 

 Denny, having received some examples of it, long 

 after it had been well known to me, considered it to 

 be an " entirely new one." Having thus far an- 

 swered Mr. T. G. Denny's rather ambiguous asser- 

 tion that the species is " not altogether new," I 

 trust he will permit me to remind him that any dis- 

 pute as to the date of acquisition, or presumed in- 

 tention of publication, is altogether beside the ques- 

 tion—priority of sufficient publication, and that 

 alone, constituting the authority of a species. I 

 submit, therefore, that in accordance with common 

 sense and scientific usage, the name given by Mr. 

 P. Walker to this new form of parasite in the 

 Science-Gossip of June 1571 must stand. — H. C. 

 Bichter, Kensington. 



