Proceedings of Irish Societies. i59 



Dublin Microscopical Club. 



The Club met at Mr. Greenwood Pim'S, who showed specimens of 

 sEcidiwn leucospermum growing on Anemone coronaria in his garden. This 

 species is stated by Plowright to be uncommon in the JEcidium stage, 

 though the Puccinia is abundant. This ^Ecidinm occurred last year on 

 the same plants, and Mr. Pirn heard of it this season in several quarters. 

 It is a remarkably pretty form, the pendial divisions being white, and 

 the spores golden yellow. 



Dr. M'Weeney showed cultivations and a slide of a curious micro- 

 organism isolated by him from purulent matter of a patient suffering from 

 pyelo-nephritis at theMater Hospital. Cultures in broth at 37 V C. develop 

 on the surface a ring of green pigmentation, which, if the depth of the 

 vessel be not great relatively to the surface, gradually extends until the 

 entire fluid is of a brilliant green colour. Young cultures briskly shaken 

 become green throughout, but the colour speedily fades save at the 

 surface. It requires atmospheric air for its development, and, as was 

 pointed out to exhibitor by Professor Hartley, the fading of the colour 

 is due to the reducing action of the living microbes in the deeper strata of 

 the broth. Cultivations of this organism exhale a most peculiar sickly 

 odour which is quite sui generis. Injected into animals it produces fatal 

 septicaemia with a sort of emphysematous swelling at the point of 

 subcutaneous inoculation. Morphologically it is a short actively inatile 

 bacillus, with a tendency to stain more intensely at the poles, like the 

 microbe of chicken-cholera. The slide was from peritoneal exudation 

 of a rabbit that had succumbed to inoculation with this microbe which 

 is perhaps identical with that described in Comptes Rendus for 18SS by 

 Galtier, under the name of Bacillus chromo-aromaticus. 



Mr. H. H. Dixon exhibited Overton's Method of fixing and staining 

 minute organisms. This process is carried out by means of a small moist 

 cell in which the material to be fixed is kept in a hanging drop on the 

 under surface of a cover-glass. In this position it may be observed 

 with the highest powers until the stage in which it is desired to fix it is 

 reached. At this moment the cover-glass is raised and a crystal of iodine 

 is introduced into the cell and the cover-glass replaced. The vapour of 

 the iodine fixes the organism, if small, almost instantaneously. The 

 water may now be replaced by some watery stain. Overton recommends 

 the replacing of the water by alcohol, in case other treatment is desired, 

 by exposing the cover-glass, on which the drop of water has been changed 

 for a drop of 20 per cent, alcohol to the vapour of absolute alcohol in a 

 small chamber. In fixing and staining fungi the spores may be sown in 

 a drop of nutritive solution which is thickened by addition of gelatine, 

 so that during the whole process the plants which develop from them 

 remain stationary ; also collapse of the cells does not occur when they 

 are transferred into glycerine-jelly. 



Dr. J. Joly showed Paraffin casts of the vessels of plants obtained by 

 himself and Mr. H. H. Dixon. In the course of some experiments upon 

 the motion of liquid in plants, they caused cut shoots of lime and elm to 

 draw up melted paraffin of low melting point (45^ C.) into the vessels. 

 On cooling and dissolving away the tissues with strong sulphuric acid, 

 paraffin casts (of extreme fineness) of the vessels were isolated. These 

 showed the pits as prominences of various shapes, and faithfully re- 

 produced all the markings upon the walls ; spiral, annular, etc. vSuch 

 casts make very beautiful microscopic objects. The method may be 

 used to determine the lengths of the vessels and their course. 



Belfast Naturalists' Field Club. 



May 19th. — Excursion to Fair Head and Murlough Bay. A party of 

 about 25 members left Belfast by the 6.30 a.m. train, reaching Ballycastle 

 at 9.30, where breakfast was partaken of. The party then drove to 



