ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 537 



present, acetic acid is reduced by the bacterium to carbonic acid and 

 water. With normal propylic alcohol, propionic acid is formed after 

 fourteen days. Methylic alcohol had to be purified before B. aceti 

 would act upon it, and then the solution became alkaline, ammonia 

 being formed ; this happened only after three weeks. B. aceti did 

 not oxidize isoprimary butylic alcohol, and the organism will not even 

 grow in amylic alcohol. From dextrose the author obtained gluconic 

 acid ; with cane-sugar he was unable to obtain any action ; from 

 mannitol, laevulose was obtained, without any acid being formed. The 

 author gives constitutional formulae for the products, constructed from 

 considerations of the action of B. aceti. He concludes by saying 

 that the above reactions " help to show that the vital functions of 

 certain organized ferments are most intimately connected with the 

 molecular constitution of the bodies on which they act." 



Micropliytes of Normal Human Epidermis.* — Dr. G. Bizzozero 

 employed the following methods for demonstrating these organisms. 



After removing the fat from the epidermis by means of alcohol 

 and ether, the epidermic scales were either (A) soaked on a slide in 

 a 50 per cent, acetic acid or a 10 per cent, solution of caustic potash, 

 and examined after putting on a cover-glass ; acetic acid preparations 

 may be permanently preserved by placing a drop of glycerin round 

 the edge of the cover-glass ; or (B) they are teased out in glycerin, 

 slightly coloured with methyl-blue, and then examined ; or (C) they are 

 placed in a small drop of 50 per cent, acetic acid on a cover-glass and 

 after soaking for a o'larter of an hour are needled out. The acetic 

 acid is then driven r ff by gentle heat, the cover-glass passed twice or 

 thrice through the flame of a spirit-lamp, the dried layer is then 

 wetted for half-an-hour with some nuclear anilin stain (methyl-blue is 

 the best), and having been next carefully washed with distilled water, 

 the preparation, when dry, is mounted in dammar or Canada balsam. 



Preparing Tubercle-bacillus.t — Dr. Glorieux has much improved 

 Neelsen's method for demonstrating the presence of tubercle-bacilli in 

 cover-glass preparations of sputum. The first step of Neelsen's 

 process is to immerse the cover-glass in the following solution : — 

 Fuchsin 1 grm. ; absolute alcohol 10 grm. ; 5 per cent, solution of 

 phenic acid 100 grm. 



The second step is to decolorize in a 25 per cent, solution of 

 sulphuric acid. It is this second stage which has been modified by 

 Dr. Glorieux, whose formula is : — Sulphuric acid 10 grm. ; alcohol 

 15 grm. ; distilled water 50 grm. Methyl-blue to saturation ; filter. 



Thus treated, cover-glass preparations may be double- stained in 

 from 60 to 90 seconds. 



Schulze's Dehydrating Apparatus. | — Prof. F. E. Schulze 

 describes a simple contrivance for securing the rapid and yet uninjured 

 dehydration of small and delicate objects. 



• Virchow's Arch. f. Path. Anat., xcviii. (1885) p. 441. See this Journal, 

 V. (1885) p. 849. 



t Bull. Soc. Belg. Micr., xii. (1886) pp. 44-8. 



J Arch. f. Mikr. Anat., xxvi. (1886) pp. 539-42 (1 fig.). 



Ser. 2.— YoL. VI. 2 N 



