ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 427 



the suspected water. If no change takes place the water is neutral ; if a 

 yellow colour is produced the water is alkaline. 



Vital Staining of Malarial Parasites.* — A. Manaud suggests the 

 use of Borrel's blue or methylen-blue for vital staining of malarial 

 parasites. Deposit a drop of the colouring matter upon a slide, and allow 

 to dry. Place upon a cover-slip a drop of the suspected blood. Place 

 the cover-slip upon the slide and lute with paraffin. Leucocytes, etc., 

 stain blue, with strongly staining nucleus. Chroniotophyllic red cells 

 also stain blue. On some of the cells one observes a blue spot con- 

 taining yellowish-black pigment, occupying a part or the whole of the 

 surface. The blue spot is darker at certain points, which may be 

 situated at the centre or at the periphery. This appearance is said to be 

 characteristic of the parasite. Basophile red cells are distinguished by 

 the regularity of their staining and by their circular outline. The 

 method is especially to be recommended for the observation of free 

 forms of the parasite after crisis. 



Biebrich Scarlet as a Plasma Stain.f — A. K. Gordon states that 

 Biebrich scarlet is freely soluble in water, and is best used in 1 p.c. 

 solution. It never overstains, and does not discharge tlie colour from 

 nuclei. Most sections are stained sufficiently in from two to five minutes. 

 It does not wash out in alcohol, clove-oil, cedarwood-oil, or xylol. It 

 stains different tissues with varying degrees of shade and tint. Muscle, 

 for example, is stained in yellowish-brown, the protoplasm of young 

 epithelial cells a bluish-pink, and the older keratinized cells bright 

 scarlet. Used after methylen-blue for tissues that have been fixed in 

 Flemming's or Zenker's fluid it does not discharge the nuclear stain. 

 The staining is of marked permanency. 



The preparation is made by British Dyes, Ltd., Huddersfield. 



Metallography, etc. 



Wire-drawing. $ — A. T. Adam gives a brief description of the 

 operations involved in drawing metal into wire, chiefly with reference to 

 steel, and of the changes in properties and structure which the metal 

 undergoes. There is an extraordinary increase in tensile strength and 

 elasticity, but hardness and brittleness do not increase in the same pro- 

 portion. The hardening effect sets a limit to the reduction in diameter 

 which can be effected without annealing. An annealing at quite low 

 temperatures removes cold work, but the best quality wires are heated 

 to temperatures above the transformation temperatures, the conditions 

 of annealing Ijeing designed to produce a sorl)itic structure which is 

 tougher and considered more suitable for drawing than a pearlitic 

 structure. Observations upon the microstructure of steel-wires con- 



* C.R. Soc. Biol. Paris, Ixxx. (1917) pp. 472-4. 



t Brit. Med. Journ., June 16, 1917, p. 828. 



^ Journ. Soc. Chem. Industry, xxxvi. (1917) No. 5, pp. 241-3. 



