June 1, 1894.] 



KNOWLEDGE. 



137 



[No doubt tbe queen's chief function is the laying of 

 eggs, and, in fact, this was the point intended to be em- 

 phasized in the passage in question. But as she is evidently 

 the central fij^ure in the hive, the prosperity of which 

 depends upon her productiveness, and as her presence 

 seems to be necessary for the orderly correlation of the 

 various duties of the workers, it would appear to be some- 

 what speculative and hazardous to deny her any sort of 

 regulative influence, such as is implied by the generally 

 used term " queen." But a moment's consideration must 

 satisfy anyone that comparisons between the beehive 

 community and human communities, as they ordinarily 

 exist, or as Mr. Denham supposes that they might exist, 

 are probably equally far from the truth. — E. A. Butler.] 



THE VENOM OF THE COBRA. 



By C. A. Mitchell, B.A.Oson. 



AMONG the most potent causes of death in India 

 must be reckoned the bite of the cobra-di- 

 capello {Niija tripwlians), the more so as the 

 reputed native remedies, natural and artificial, 

 all fail as antidotes to the venom when once 

 introduced into the system. 



Experiments made by various chemists have deter- 

 mined the chemical nature of the poison, though, owing 

 to the difficulty and danger of procuring sufficient for the 

 purpose, there are few quantitative results published. 



To procure the poison the reptile, which is firmly held 

 by a native snake-catcher or strapped down by the neck, 

 is made to strike repeatedly at a large leaf, on which the 

 venom fi-om the fangs collects. 



As first obtained it is a frothy liquid, varying in colour 

 from pale amber to yellow, and according to Dr. Wall 

 occasionally colourless. Its specific gravity as compared 

 with water is 1-058. It may be kept in a stoppered bottle 

 for some months without material change, but eventually 

 decomposes, giving ofl' carbonic acid gas, and losing its 

 toxic properties. Bacteria are found in abundance in the 

 fresh liquid venom, as well as particles of epithelial 

 matter, the latter being more noticeable after the liquid 

 has been kept for a short time. The bacteria are derived 

 from the saliva of the snake, and have been proved to 

 add no additional virulence to the poison. When allowed 

 to dry in the air it leaves a yellowish film, which breaks 

 up into yellow granules of crystalline appearance, resem- 

 bling particles of gum-arabic. This residue preserves all 

 the venomous properties of the fresh poison unchanged 

 for years, as has been proved by experiments made on 

 animals with venom that had been kept for over twenty 

 years. Solution in glycerine is also found to be efi'ective 

 in preserving the toxic properties. The yellow granules 

 are said to possess a sharp acrid smell, though this was 

 not noticeable in some which the writer exammed, which 

 had been kept for several years. On heating this old 

 sample in a platinum basin it swelled up into a coke-like 

 mass, giving oft' ammoniacal vapours, and on ignition left 

 a slight ash in which sodium chloride was detected. The 

 ash amounted to 1'5 per cent., calculated on the weight 

 of the dried poison. 



It has often been asserted that snake-venom contains an 

 animal alkaloid similar to the ptomaines found in putrefied 

 animal matter, but this view is not supported by the 

 majority of chemists. Though in some cases precipitates 

 may be obtained with the ordinary test reagents, they are 

 not distinctly crystalline as in the case of the alkaloids. 

 There is a class of complex substances containing a large 



percentage of nitrogen, and found chiefly in the animal 

 world, to which the name of protiids or uUiumimiiil bodies 

 is given. Egg albumen, which constitutes nearly the 

 whole of the solids in the white of the egg, may be taken 

 as a tvpe of the proteid bodies, the average percentage 

 composition of which is — 



Oxygen, 21 to 23-5. 



Hydrogen, 7. 



Nitrogen, 15 to 17. 

 When exposed to the action 

 such as are contained in 

 albumen is converted into 



Carbon, 51-5 to 54-5. 



Sulphur, 3 to 2. 



Ash, variable, 

 of acids, either mineral or 

 the gastric juice, any animal 

 a substance known as peptone. 



which, while of similar composition, differs in several 

 respects in its behaviour towards reagents, and especially 

 in its power of diffusing through a membrane such as 

 parchment. There is also another albuminoid substance 

 very similar to egg albumen in its chemical composition, 

 but difl'ering from it in being insoluble in pure water, 

 which is known as ghihidin. 



The complex nature of cobra venom has been noticed by 

 many investigators, but Prof. Armstrong was the first to 

 make a quantitative analysis of a small quantity of the 

 liquid venom, sent to him by Sir J. Fayrer. He found 

 that it left, on evaporation, a residue amounting to 28-128 

 per cent, of the weight taken, and that this residue, on 

 analysis, gave the following percentage composition, after 

 deducting the amount of ash : — 



Carbon 52-87 



Hvdrogen ... . . ... 7-05 



Nitrogen 18-29 



Oxygen and Sulphur ... 21-33 



99-54 



This closely corresponds to the general composition of 

 albumens, but contains more nitrogen than egg albumen. 

 Prof. Weir Mitchell, in a long series of experiments, 

 proved that there were two albuminoid bodies in the 

 venom. By means of a parchment membrane floated on 

 running water, on which the venom was placed, he 

 succeeded in separating the two. The coagulable proteids 

 were left on the membrane, while the dialyzable matter 

 passed through. The substance deposited gave all the 

 reactions oi ylohulin. In the filtrate containing what had 

 passed through the membrane was foimd a substance 

 which could be precipitated but not coagulated by absolute 

 alcohol, which property, among others, entitled it to be 

 placed among the peptones. He thus identified two classes 

 of proteids : — 



1. A <ilobuUn — Coagulable and insoluble in pure water. 



2. A peptone — Incoagulable by brief boiling and soluble 



in pure water. 

 There was one noticeable peculiarity about this venom 

 peptone : although it did not coagulate at first on 

 boiling, yet after some time it became coagulated, being 

 apparently converted into a globulin. In this respect it 

 differed from ordinary peptones. Careful experiments on 

 animals proved that it was in the peptone that the toxic 

 principle of the venom lay. Pedler succeeded in obtaining 

 a yellow semi-crystalline precipitate with this poisonou.s 

 principle by platinic chloride, which diS'ered, however, 

 from that obtained with alkaloids in being less crystalline ; 

 and a similar result has been obtained by the present 

 writer. 



Owing to the similarity between the albuminoid 

 substances in the venom and those in the blood, there 

 is not much chance of finding an antidote which will 

 neutralize the former without also injuring the latter. 

 It has been found that the strength of the poison is not 



