ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 403 



few days, the slice of bone was ground smooth on one side, and then 

 treated with the silver solution for a week or two in the dark. After 

 this it was permeated with balsam, and the other side ground down in 

 the usual manner. 



Dental Histology.* — Those interested in dental histology will find 

 an excellent and useful account of the various processes necessary for 

 demonstrating the structure and appearances of normal and diseased 

 teeth in the article by Mr. L. Strangways, which, though covering a 

 great deal of ground, is extremely concise. 



New Liquid for Counting Blood-corpuscles.f — M. G. Hayem has 

 found the followiag fluid very satisfactory as a menstruum for counting 

 blood-corpuscles : — Distilled water 200 grm. ; sodium chloride 1 grm. ; 

 sodium sulphate 5 grm. ; solution of iodo-potassic iodide 3-4 ccm. The 

 iodo-potassic iodide solution is composed of: distilled water 500 grm. ; 

 potassium iodide 25 grm. ; iodine in excess. The amount of the iodine 

 solution varies for different animals; for man it is 3*5 ccm. 



Biological Test for Arsenicf — Herren E. Abel and P. Buttenberg, 

 in an article on the action of mould fungi on arsenic and its compounds, 

 deal with the demonstration of the metal by means of cultures. The 

 results of Gosio and Abba § are confirmed, and the authors find that for 

 the qualitative determination of arsenic this method is universally 

 applicable, and is more sensitive than chemical tests. The mould used 

 was Penicillium brevicaule, and the medium a sterilised mash of mouldy 

 bread. At 37° and often within 24 hours, and always in from 48-7*2 

 hours, the growth was so luxuriant that the characteristic garlicky odour 

 was perceptible. In this way 0*00001 grm. As 2 3 and often 0- 000001 

 grm. could be detected. Of metallic arsenic less than 0*0001 grm. could 

 not be clearly demonstrated. 



The method is applicable to any substance or compound or structure, 

 such as chemical solutions, skins, hides, carpets, paper, woven fabrics,, 

 foodstuffs, and beverages of all descriptions. The presence of arsenic in 

 minute quantities in human and animal bodies was easily demonstrated, 

 and in the living subject a dose of 5 drops of liquor arsenicalis was 

 detected. 



Method for Sticking Celloidin Series with Water and Albumen. i| 

 — Prof. P. Argutinsky communicates the following simple and satis- 

 factory method for sticking celloidin sections on slides. The slide is 

 carefully cleaned from grease by means of spirit and heat. A small 

 drop of Mayer's glycerin-albumen is placed on each slide, and spread 

 out into a very thin layer. The albumen is then coagulated by warm- 

 ing the slide. The sections, cut under 70 per cent, alcohol, are carefully 

 straightened out and removed with a dipper to the slide, and then covered 

 with alcohol. If the sections be not quite smooth, they must be replaced 

 in alcohol to be straightened out. "When the sections are satisfactorily 

 arranged, the alcohol is removed by touching the long side of the slide 



* Illust. Ann. Microscopy, 1900, pp. 61-70 (9 figs.). 

 t C.R. Soc. Biol., vi. (1899) p. 265. 



X Zeitschr. f. Hygiene u. Infektionskr., xxxiii. pp. 449-90. See Centralbl. Bakt. 

 u. Par., 2 te Abt., vi. (1900) pp. 187-9. § Cf. this Journal, 1899, p. 239. 



|| Arch. f. Mikr. Anat. u. Entwicklungs., lv. (1900) pp. 415-19. 



2 E 2 



