26 



HARD IVICKE'S SCIENCE-GOSSIP. 



the indurations induced by them. Where mucous 

 membranes and portions of the integument are to be 

 indurated, chromic acid will be the most applicable 

 of these reagents for bony structures, or ossified 

 tissues, taking care to add to the solution 4 or 5 drops 

 of muriatic acid to every 8 ounces. 



Lastly, alcohol must be employed for the hardening 

 of all tissues which have been injected. 



(e) Picric acid : — (Kleinenberg) for hardening soft 

 sarcomata, myxomatous and embryonic tissues, me- 

 sentery, &c. Make as follows : — Saturated watery 

 solution of picric acid, 100 parts. Strong sulphuric 

 acid (IL S 4 ), 2 parts. Filter to remove yellow 

 precipitate which is formed, and add distilled water, 

 300 parts. It hardens the above tissues in from 3 to 

 12 hours. 



(3.) Cutting sections : — An inexpensive section 

 knife can be made by grinding the upper side of a 

 common razor blade into a concavity, and the under 

 surface quite flat. You will have a simple but quite 

 as effective an instrument for your purpose as can be 

 devised. Of course a microtome is the best. I 

 strongly recommend Cathcart's as a good and cheap 

 instrument, but the razor can be made to answer 

 your purpose quite well. Keep it well wetted 

 with alcohol while using, and slice your sections off 

 rapidly, and in one sweeping motion of the hand 

 immerse each at once in alcohol. If the tissue is too 

 small to hold in the hand, imbed in wax, paraffin, 

 cellodin, &c. 



(4.) Staining sections : — There are so many dif- 

 ferent stains, that it would be impossible here to enter 

 into full details of each. Therefore I shall content 

 myself with naming those I have found the most 

 useful. Logwood, carmine, methylanilin violet, 

 methylene blue, anilin blue-black for nerve cells, 

 picro-carmine, and osmic acid. 



Bismarck brown and iodine green for double- 

 staining. I would recommend students to buy the 

 stains ready-made, as they are much more certain in 

 action, and save a large amount of time. For 

 staining in picro-carmine, see pp. 275 and 276 of 

 Vol. XX., Dec. 1884, of this paper. In staining in 

 methylanilin violet, soak the sections in a watch-glass 

 for about two or three minutes in a watery solution ; 

 wash well for half an hour in water, and mount in 

 glycerine, either pure or according to Cornil, slightly 

 acidulated with acetic acid. Farrant's solution may 

 also be used as a mounting medium. Do not use 

 Canada balsam or dammar, as both clove oil and 

 alcohol dissolve out the colour, and even the chloro- 

 form used as a solvent for dammar and balsam acts 

 in a like manner on the stain. 



Anilin blue-black can be made as follows : — Anilin 

 blue black, I part. Water, 40 parts. Dissolve and 

 add rectified spirit, loo part. (Bevan Lewis.) 



Staining, filter a few drops into a watch glass, and 

 add 8 or 10 times as much alcohol to it. Soak from 

 i to 3 minutes, and mount in C. balsam. If the 



staining is too deep, soak the sections for a time in a 

 2 per cent, solution of chloral hydrate. (Stirling.) 



Bismarck brown ; sections must be stained slowly, 

 and the water in which the staining fluid is suspended 

 must contain about 10 per cent, of methylated spirit. 

 Make a straw-coloured solution, and allow sections 

 to remain in this for several days. Mount in C. 

 balsam. Where used as a contrast stain, pour a 

 few drops of the strong solution into a watch-glass, 

 and allow the section to remain in this for about 

 IO minutes. 



Methylene blue : — {saturated solution) dilute with 

 about 5 times its volume of water, mount in glycerine 

 or Farrant's solution. 



On double and treble staining morbid growths: — 

 Well-hardened sections of rodent ulcer and epithel- 

 ioma may be stained by the picro-carmine and 

 logwood process, others of same material with 

 rosanilin and iodine green, and compare them. 



Amyloid degeneration, hardened in chromic acid, 

 stain with rosanilin hydrochloride and iodine green, 

 or eosin and anilin blue, a 1 per cent, solution of 

 safranine gives a good result, and so does methylanilin 

 violet, and iodine. The specimens are then mounted 

 as ordinary preparations. (For the more complete 

 list of staining reagents, see "Postal Journal," July 

 and October, 1885.) 



Before ending this paper, I would strongly urge 

 students to get up normal preparations well, before 

 beginning morbid, or they will otherwise be com- 

 pletely at sea, if I may use the term. 



Summary : — 1st day. Small pieces placed in 

 chromic acid mixture. 



2nd day. Fluid, changed. 



5th >» »> » 



8th ,, ,, ,, 



9th day. Spirit mixture, i.e. 1 part of water to 2 

 ofmethy. spirit. 



10th day. Pure methylated spirit. 



14th 

 15th 

 16th 



Plain water. 

 Mucilage. 



,, Section cut, stained, and mounted, 

 (Gibbs.) 



The following papers and books may be of use to 

 students : — 



(Coats.) Pathology. 32s. 



(Gibbes.) Practical Histology, &c. 5s. 



(Green.) Pathology. 1 2s. 6d. 



(Cole.) Methods of Microscopical Research. 5.5-. 

 And Pathological Studies. 21s. 



(Cornil and Rauvier.) Pathology. 25J. 



(Woodhead.) Practical Pathology. 24s. 



(Ziegler.) Pathology vols. i. ii. iii. 12s. 6d. each, 

 and various Journals, especially the Royal Micro- 

 scopical, Years, 1883, 1884, and 1885, and Quekett, 

 &c. &c. 



Sir F. J. O. Evans, F.R.S., late Hydrographer 

 to the Admiralty, has just died, in his 71st year. 



