74 



HARDWICKE'S SCIENCE-GOSSIP. 



washed for a few minutes each, in alum-water, pure 

 water and fifty per cent, alcohol. Finally it is put 

 in pure alcohol until transferred to the blue. 



Carmiue and aniline blue produce marked stain- 

 ings, but they are rather glaring to the eye under 

 the glass. I use an ammoniacal solution of the 

 former, double the strength of Beale's, substituting 

 water for glycerine. In this a section is kept for 

 several hours. On removal it should be dipped in 

 water, and then put for a few minutes in alcohol 

 acidulated with two per cent, cf nitric acid ; then in 

 pure alcohol ; then in the half-grain blue solution 

 before spoken of, from which it should be removed 

 to alcohol ; then to oil of cloves. Much colour will 

 be lost in the acid alcohol. The acid is to neutralize 

 the ammonia, which is inimical to aniline blue. 

 Magenta aniline or haematoxylon may be used with 

 green instead of blue aniline. The brand of green 

 I prefer is the iodine brand, one grain to the ounce 

 of alcohol. 



Double stainings of sections of leaves in which red 

 is first used, have the spiral vesesls stained this 

 colour, other parts being purple or blue. Radial 

 and tangential sections of wood have the longi- 

 tudinal woody fibres red, and other parts purple or 

 blue. 



This selection of colour is, I think, due to the 

 fact that spiral vessels and woody fibres take up 

 more red than other parts, and are slower in parting 

 with it. The blue, therefore, seems first to overcome 

 the red in parts where there is less of it. It will 

 entirely overcome the red if sufficient time be given. 



If the blue be used before the magenta aniline, 

 the selection of colour is reversed. 



I would here call special attention to the import- 

 ance of examining these stainings at night, as the 

 red in them has a trace of blue iu it which does not 

 show at that time, but comes out so decidedly by 

 daylight, as to change, even spoil, the appearance of 

 the specimen. 



I think they should be mounted in Canada balsam, 

 softened with benzole, as the presence of the latter 

 may be beneficial in preserving its magenta. 



I would offer a few words upon section-cutting, 

 and upon preparing sections for dyeing. 



To cut a thick leaf, place a bit of it between two 

 pieces of potato or turnip, and tie with a string. Cuts 

 may be made along the midrib, or across it, including 

 a portion of leaf on either side, or through several 

 veins. Fine shavings of wood may be used, or 

 pieces rubbed down on hones. 



Sections of leaves may be decoloured for staining 

 by placing for some time in alcohol ; but I would 

 recommend the use of Labarraque's solution of 

 chlorinated soda, for a few hours after the alcohol. 

 Especially do I recommend the Labarraque for all 

 kinds of wood. In twelve hours wood is generally 

 bleached; too long a residence in it will, however, 

 often cause it to fall in pieces. 



After removing from the soda, wash through r. 

 period of twelve or eighteen hours in half a dozen 

 waters, the third of which may be acidulated with 

 about ten drops of nitric acid to the ounce, which 

 acid must be washed out. Next put in alcohol, in 

 which sections and also leaves may be kept indefi- 

 nitely, ready for dyeing. 



Before closing this I would add a few suggestions 

 concerning leaves not contained in my January 

 article. 



Magenta, when used for them, should be of the 

 strength of one-eighth or one-quarter of a grain to 

 the ounce of alcohol, and purples and iodine-green 

 two or three times as strong. These anilines are 

 inferior to the blue in bringing out all the anatomical 

 parts of a leaf, including the beautiful crystals so 

 often met with. On removal from the dye, leaves 

 should be thoroughly brushed with camel-hair 

 pencils. 



One week, instead of forty-eight hours, is fre- 

 quently required to effect the decoloration of large 

 leaves in chlorinated soda, even when they are cut 

 into several pieces, which is advisable. 



Mr. L. R. Peet, of this city, whose stainings iu 

 aniline are unsurpassed for beauty, thinks better 

 results are attained by commencing with a weak 

 dye, say from one-tweutieth to one-twelfth of a 

 grain, and slowly increasing the strength of the dye, 

 at intervals of from one to three hours, until the 

 required hue is obtained. This process certainly 

 guards against too deep staining, and may give a 

 finer tone to leaves under the glass. 



Baltimore, U.S.A. 



OUR JACK. 



HAVE you ever kept a pet magpie? If not, you 

 ought by all means to get one ; for of all the 

 amusing, interesting, impudent specimens of the 

 bird tribe, it is the greatest. We have one, which 

 we have reared from the nest, and most fully has 

 it repaid any small amount of trouble expended upon 

 it. One day early in May last year, one of our 

 brothers brought in from a distant fir plantation 

 what looked like two awkward-looking animated 

 dumpy balls of black and white feathers. On 

 looking closer, these were discovered to be in 

 possession of a beak and eyes each, and pronounced 

 to be young magpies. They were immediately 

 adopted by the family, and endowed with the well- 

 known names of Jack and Jill. Of their babyhood 

 there is not much to chronicle, except the eagerness 

 with which they gulped down spoonfuls of bread 

 and milk every few hours, and the obstinacy with 

 which they refused to perch at night, usually pre- 

 ferring to sit upon each other's back, being warmer 

 for the feet than a cold perch. As, however, both 

 could not have the most comfortable position, there 



