BIOLOGICAL LECTURE.

Otago Daily Times, Issue 6385, 31 July 1882, Page 3

BIOLOGICAL LECTURE.

The third and iaßt of a very interesting series o lectures on " Fermentation and Putrefaction jvasdeliveredbyProfessorParkerfntheMuseuni on Saturday evening. The excessively stormy weather unfortunately prevented the usu^l «ood attendance, but some 30 persons braved the eleiaeate in order to hear the conclusion of X eubiect which has been followed with great interest by the .alienees on each former occasion- Spontaneous generation, heterogenesis, the germ theory of disease were the benches of the g ubkct <fcaft with by Pro. fesSL-r Parker on Saturday. Tho theory of oramUneous generation, or atwgeßesw. it was explained, (supposed that living organisms ~u>.Qse 2>wvo, either from inorganic matter or from dead oreauie matter. It was opposed by the theory of biogenesis, or panspermism, which supposed that life .ofljy CAme from pre-existing Vie at least so far gs .bWwtlon and induction could be carried. The befell m spontaneous w£e many of the educated classes who believed in the spontaneous generation of frogs. The first Wow to the theory was gH'en in IMS hv the Italian Kedi, who proved that if meat, which was particularly liable to corruption frmn maggots, were covered securely by a wire screen, these jnaggois did not appear. Redi tijas demonstrated fchaJt jtjiese really arose from emM laid upon the meat by flies. No one now pretended that the higher organisms arose spontaneously. In modern times, inquiry as to the theory of abiogenesis had all eentrsd around bacteria .and monads, the lowest exisir ing organisms. The whole issue was narrowed down to this; If flnyfluid capable of putrefaction was exposed fr> the air, putrefaction fvould inevitably opffl»r,#nd ijhis ,vas always accompanied by the appeawes.of bacteria and . Monads. The question was, wore these of spontaneous generation,.or were th.ey the result o?^erias in the air finding *eir way to the fluid! To prove this latter theory, it was necessary to show that if the access of germs tea pntresdtfe fluid (the existing germs an which had been previously .destroyed by heating Were prevented, the fluid .would show no silos of life. The present of germs,of some sort in the air had been proved by *««™«. •? and examining iuapended partjejes. And their access to pntrescible flukls, previously pterilised by boiling, had been prevented in vnrum ways. These were:—(l) By hermetically aenh inir the containing vessel during ebullition. 12) By allowing the acco*» of calcined air only. (3) By filtering air through cotton wool. (4) By filtering it through long #«c tubes, as performed by. Pasteur. (5) JJy allowing IH .germs to subside in a confined raace of pWi air as performed by Professor Tyndall. The inrariaUc result of experiments properly conducted in this way had been & show that n.ntrescible fluids thus confine4did not jmtrcfy. lecturer illustrated th.ia by Rowing his

audience various experiments, performed months ago, on such fluids an milk, infusions of fish, meat, turnips, &c, putrefaction haying in each case been completely prevented. Ihw, to him, appeared convincing proof of tho fallacy of tho doctrine of spontaneous generation or abiogonesis. As regarded tho theory of heterogonosis, it supposed that well-characterised organisms arose by transformation in tho courso of a singlo generation of othor organisms ; and it was opposed by the theory of liomogenesis, according to which offspring always resembled the parent in essential characteristics. Researches iuto tho development of animals and plants showed a definite eories of changes to bo always gone through in the passage from tho embryonic to the adult state, and this showed hotorogenesis to be inherently improbable, all cases in which it had been supposed to occur having been due to erroneous observation. The lecturer concluded by dealing with tho germ theory of disease, which had been proved to be true in certain cases by establishing a, definite connection botwuiiii phases in the life history of bacteria and phiisvs of the disease.