Mar. 23, 1888.] 



SCIENTIFIC NEV\AS. 



281 



of papers, Hectares, etc* 



ROYAL SOCIETY. 

 At the meeting on March 8th, the following communi- 

 cations were read : — 



" On some New and Typical Micro-organisms obtained 

 from Water and Soil." By Grace C. Frankland and 

 Percy F. Frankland. Communicated by Professor T. H. 

 Huxley. 



The authors have already given a detailed description 

 of a number of micro-organisms — bacilli and micrococci 

 — which they had obtained in the course of investigations 

 on the distribution of micro-organisms in the atmosphere. 

 The present paper deals with micro-organisms which 

 they have derived from various natural waters. The 

 authors point out the striking difference between the 

 aerial and aquatic micro-organisms, micrococci being the 

 predominant forms amongst the former, whilst bacillar 

 forms are almost exclusively present in water. It was 

 found that whilst none of the forms described oxidised 

 ammonia either to nitrous or nitric acids, several of them 

 exerted a powerfully reducing action on nitrates, others 

 were without any action on the nitric acid, and 

 others again caused the disappearance of an appreciable 

 proportion of the nitric acid without production of a 

 corresponding amount of nitrite. The authors allege 

 that these differences in the behaviour of micro-organisms 

 when introduced into solutions containing nitrates furnish 

 very important data for distinguishing between approxi- 

 mating forms. Thus Bacillus subtilis and Bacillus cereiis, 

 though closely resembling each other, can be easily dis- 

 tinguished by the behaviour which they respectively ex- 

 hibit towards the nitrate-solution. The Bacillus subtilis 

 has no action on the nitric acid which can be quanti- 

 tatively recovered, whilst the Bacillus cereus powerfully 

 reduces the nitrate with formation of nitrite. The solution 

 employed for the purpose of these experiments contained 

 potassium phosphate, magnesium sulphate, calcium 

 chloride, calcium nitrate, invert sugar, peptone, and an 

 excess of calcium carbonate. 



The following is a brief account of the descriptions 

 given of the various micro-organisms : — 



Bacillus arboresccns is a slender bacillus giving rise 

 to wavy threads, sometimes of considerable length. No 

 spores were observed. In drop cultivations it is seen to 

 be vibratory. On potatoes it produces a fine deep- 

 coloured orange pigment. On nitrates it has no action 

 in the solution employed. 



Bacillus aquatilis is a slender bacillus also giving rise 

 to wavy threads. No spores were observed, and the in- 

 dividual bacilli are seen in drop cultivations to exhibit 

 only an oscillatory motion. It grows with great difficulty 

 in all the media employed, with the exception of the 

 aqueous solution, in which it grows abundantly, but 

 does not reduce the nitrate. 



Bacillus liquidus is a short fat bacillus of very variable 

 dimensions. It produces on potatoes a thick flesh- 

 coloured pigment. It reduces the nitrate powerfully in 

 the solution employed. 



Bacillus vcrmicularts is a large bacillus with rounded 

 ends, giving rise to extensive vermiform threads. It 

 produces fine oval spores, and has a strong reducing 

 power. 



Bacillus nubilus is a fine slender bacillus, which gives 



rise to wavy threads. Its growth in the solution effects 

 the reduction of a very small proportion of the nitrate to 

 nitrite. 



Bacillus ramosus is a large bacillus much resembling 

 B. subtilis, giving rise to long threads and spores, which 

 are, however, rounder in shape than those of the latter 

 organism. When grown on potatoes, it forms a dry 

 continuous surface expansion, which is nearly white. 

 It exerts a powerful reducing action on nitrates in the 

 solution employed. 



Bacillus aurantiacus is a short fat bacillus of very 

 variable dimensions. On gelatine plates it produces 

 bright orange pin-heads, but on potatoes it gives rise to 

 a brilliant red-orange pigment, extending not far from the 

 point of inoculation. It reduces the nitrates to nitrites 

 only very slightly in the solution employed. 



Bacillus viscosus is a short bacillus about three or four 

 times as long as broad, occurring mostly in pairs. It 

 very rapidly liquefies the gelatine, rendering it very 

 viscid, and colouring it green. On agar-agar the whole 

 surface quickly turns green. No reduction of the nitric 

 acid takes place. 



Bacillus violaceus is a bacillus varying in thickness, and 

 produces on agar-agar a fine dark violet expansion. It 

 powerfully reduces nitrates to nitrites. 



Bacillus diffusus. — A fine slender bacillus recurring 

 frequently in pairs, and giving rise occasionally to long 

 undulating threads. It slightly reduces the nitrates to 

 nitrites. 



Bacillu scandicans. Sometimes this bacillus has almost 

 the appearance of a micrococcus, at other times it shows 

 a tendency to grow into short threads. When grown on 

 gelatine plates it produces surface expansions much 

 resembling drops of milk. 



It grows abundantly in the aqueous solution, but exerts 

 no reducing action on the nitric acid. 



Bacillus scissus. — In form this organism much resem- 

 bles Bacillus prodigiosus. It produces pale light green 

 surface expansions on gelatine plates. In tubes the 

 gelatine and agar-agar become tinted green. It power- 

 fully reduces nitrates to nitrites. Of the above, the first 

 nine were derived from water, whilst the remaining three 

 were obtained from garden soil. 



" Further Observations on ihe Electromotive Proper- 

 ties of the Electrical Organ of Torpedo marmorata." By 

 Francis Gotch. Communicated by Professor J. Burden 

 Sanderson, F.R.S. 



The author details the results ot experiments on the 

 electromotive properties of the electrical organ of the 

 Torpedo carried out in October, 1887, at the laboratory 

 of the Societe Scientifique d'Arcachon. 



From du Bois-Reymond's experiments it would appear 

 that the organ possesses the remarkable property of con- 

 ducting an intense current of short duration, led length- 

 wise through its columns, better when the current is 

 directed from its ventral to its dorsal surface than when 

 directed the reverse way. The former direction coin- 

 cides with that of the current of the shock of the organ, 

 and is therefore termed by him " homodromous ; " the 

 latter being opposite in direction, is termed " heterodro- 

 mous." The evidence rests upon the value of the 

 galvanometric deflections obtained when both cur- 

 rents are allowed to traverse a strip of organ and a 

 galvanometric circuit. The deflections are markedly un- 

 equal, particularly when induced currents are used, the 

 homodromous effect being always much greater than the 

 heterodromous. The homodromous current must there- 



