HARDWICKE'S SCIENCE-GOSSIP. 



61 



the former are longer and bright red for the upper 

 two-thirds of their length ; the two kinds merging 

 gradually into one another. This position of the 

 abortive stamens is just that in which they would be 

 of least use to the pistil even if they had anthers, 



A Novel Air-pump for removing Air Bubbles 

 in Slides. — A is a frame made of wood or metal ; B 

 is an india-rubber pipe ; C is a valve made^ by 

 closing one end of a piece of glass tube, and then 

 drilling a small hole as shown in D, then slipping 



Fig. 59. — Stamens of Spartnannia Africana (magnified 15 diameters). 



supposing the flower to be self-fertilising ; while it is 

 also here that the stamens would be most likely to 

 undergo metamorphosis into petals. 



As one might expect a flower with so many stamens 

 to have a tendency to become double, it would be 

 interesting to know what would be the effect of 

 cultivation, and whether the malformation would 

 advance inwards as the outer stamens were converted 

 into petals. It may be that instead of becoming 

 petals, the outer stamens would produce still more 

 extraordinary forms. 



I am indebted for the specimen I have figured to 

 J. W. Morris, Esq., of Bath. 



New-Ki7igswood, Bath. John W. Buck. 



MICROSCOPY. 



Cavities in Quartz.— The observations made 

 upon the liquid-cavities in the quartz-bearing rocks 

 of the Lake District were made from thin slices of 

 the rocks prepared for me by Mr. Cuttell, under the 

 superintendence of Mr. Jordan, of the Museum, 

 Jermyn Street. Mr. Jordan has invented a special 

 form of machine for the purpose. I would refer readers 

 of Science-Gossip to my paper in the "Quarterly 

 Journal of the Geological Society," vol. xxxi. p. 568, 

 1875. — J. Clifton Ward. 



over it a small piece of india-rubber tubing as showro 

 at C. The top of frame A should be made perfectly 

 true, and then coated with tallow and a piece of glass- 



Fig. 60. — Air-pump for removing air-bubbles. 



laid upon it. The air is exhausted with the mouth 

 at C. I find with this handy little instrument I 

 can get sufficient vacuum to remove any air bubbles 

 that might have formed in my slide. Mr. Atkins, 

 of 200 Essex Road, Islington, made my instrument, 

 and I think he is now making them for sale. — 

 A. Smith. 



How tq remove Canada Balsam from Slides. 

 — I know that microscopists sometimes find it difficult 

 to remove Canada balsam from old slides, or un- 

 successfully mounted ones. I have always found the 

 following plan a very good one : Place the slides in 



