SCIENCE- GOSSIP. 



9* 



Patterns in Glycerine-jelly Mounts (figs. 3 

 and 4). — Many years ago I was much troubled with 

 the beautiful patterns produced by the vaporisation 

 of glycerine jelly. After spoiling a number of 

 slides I decided to do no more glycerine- jelly 

 mounts, but to keep to balsam. An earwig's wing 

 which I mounted in the " eighties" kept very well 

 till quite lately, and then went in this way. I 

 wish some member would photograph this vapor- 

 ised jelly ; it is just like a wall-paper pattern, and 

 every branch seems to join on continuously. I 

 have never seen a more beautiful example. — G. H. 

 Bryan. 



I have photographed the "vaporised jelly" as 

 Dr. Bryan wishes. The narrow portion of the 

 pattern is the jelly, and the wider part the 

 vacuoles. — J. J. Wilkinson. 



This beautiful wavy pattern arises, I think, from 

 shrinkage of the mounting medium, whether 

 glycerine jelly or not I cannot say. I have 

 mounted many objects in that medium, and have 

 many now of some years' standing, but have never 

 had a slide turn out like this. In my case the 



<?"4te 



sections would have been improved by a little 

 longer treatment with acid alcohol. In my opinion 

 there is no better stain for animal tissues than 

 haematoxylin, and especially Ehrlich's ammoniated 

 haematoxylin. I would rather part with all the 

 other microscopical stains than this. I would 

 suggest the use of this stain for animal sections 

 in preference to carmine, together with eosin as a 

 contrast stain. Carmine and haematoxylin are 

 nuclear stains ; picric acid is a plasmatic stain and 

 cannot supplant a nuclear stain like carmine, but 

 may be used after it or in conjunction with it, as in 

 the well-known picro-carmine stain. The only 

 disadvantage raised against haematoxylin as a 

 stain is that it is thought not to be permanent. 

 This may be the case with some preparations, but 

 I have not found it so with Ehrlich's. The aniline 

 stains, though permanent and capable when skil- 

 fully used of giving very fine results, and also of 

 being very useful for special purposes, require care 

 in their use, and are not very suitable to be put into 

 the hands of a beginner. Further, they are quite 

 unsuitable for celloidin preparations. I have used 



Figs. 3 and 4. Patterns in Glycerine-jelly Mounts. 



jelly has always filled up the space under the 

 cover-glass, whereas in the present instance it only 

 partially fills the space, the rest being air, so that 

 there is room for expansion or shrinkage. This, 

 however, is only my idea ; and as Dr. Bryan has 

 some slides mounted in jelly which have acted in 

 a similar manner, his view of the cause may be the 

 correct one. — John Hiooert. 



Carmine and Picro-carmine as Stains.— I 

 would like to enter a protest againstl the use of 

 carmine stain. One cannot get rid of the little 

 particles of carmine that so plentifully bestrew the 

 objects [histological sections, Ed.] It is the same 

 with haematoxylin. The colour is but mechani- 

 cally suspended, whereas in picric acid and the 

 aniline dyes the stain is chemical and leaves no 

 deposit. — Adam Clarke Smith. 



I am afraid I do not follow Mr. Smith's objec- 

 tion to the carmine stain. In the slide referred to 

 there are to be seen abundant tissue nuclei stained 

 deeply with carmine, and in places shreds of tissue 

 that have become loosened during mounting ; but 

 I nowhere observe particles of carmine " bestrewing 

 the objects." Carmine is certainly not a good 

 stain for most animal tissues, being more service- 

 able for the nervous system and for vegetable 

 sections. I find it, however, the most convenient 

 stain to use for celloidin sections. Some of the 



picric acid in conjunction with aniline blue as a 

 nuclear stain, but the differentiation is not so 

 sharp and the result not so good as that obtained 

 by haematoxylin and eosin. — J. JR. L. Dixon. 



I have seen some very good slides prepared in 

 Germany by injecting the blood-vessels with a 

 solution of gelatin coloured, I believe, with 

 cochineal. I have had some of these slides more 

 than twenty years, and the colour is as good now 

 as at the first. The condition of the epithelium of 

 a mucous membrane can be readily seen, and 

 this is important in some diseases. — F. Bossey. 



In picro-carmine staining slides of the same 

 tissue are interesting if put up with: (a) Picro- 

 carmine and Warrant's solution ; (b) picro-carmine 

 and Canada balsam; (c) picro-carmine, followed 

 by water acidulated with picric acid, a few drops 

 being placed in a watch-glass of water. The 

 results vary, and it is worth noting which come 

 out best: Treble staining has a great future, and 

 the extra trouble is well repaid. I have for some 

 time worked at the latter, and find that a most 

 beautiful combination to use is a weak solution of 

 the carmine, ten drops in a watch-glass of water, 

 followed by rosaniline, and finally by gentian 

 violet. — T. P. Thomson. 



[For further articles in this number on Micro- 

 scopic suhjects, see pp. 68, 70, 71, 76, and 77.] 



