May 24, 1883] 



NA TURE 



8j 



tity of "betterness" or " worseness " in an ingot being 

 added to or subtracted from the weight of it, gives the 

 quantity of standard metal contained in it,'' and that 

 therefore the " betterness " or " worseness " affords a 

 ready means of determining the amount of copper or gold 

 required to standardise the whole. Further, if a number 

 of ingots of varying weights and fineness have to be dealt 

 with, a similar result will be arrived at by taking the 

 algebraical sum of the several products of their weights 

 and "betterness" or "worseness." These advantages, 

 however, apply to individual calculations, and become 

 unimportant when standarding tables adapted to the 

 decimal system are available. 1 



In a letter to Mr. Fremantle, Prof. Roberts advocated 

 the abolition of this old system of carats and grains and 

 the adoption of the decimal system. This has accordingly 

 been carried into effect. Gold of the value of two millions 

 sterling has recently been imported for coinage, and the 

 simplicity and accuracy of the new system has been 

 abundantly demonstrated. 



The facts above stated may seem comparatively unim- 

 portant in themselves, but the Mint may at any time be 

 called upon to coin (as was the case in 1S72) fifteen 

 millions sterling of gold in a single year, and extreme 

 care has to be taken to insure accuracy in the standard 

 fineness of the metal. It is curious that the old system 

 described above should not have given place before now 

 to that which has long been adopted in other countries. 



THE POISONOUS LIZARD* 



""PHE Gila Lizard of Arizona and Sonora has anterior, 

 *■ deciduous, grooved teeth, which communicate by 

 ducts with large glands within the angle of th >wer jaw 

 — an apparatus so strongly resembling the poison-fangs 

 of serpents as to suggest that this lizard has venomous 

 properties. It is said by the natives of Mexico to be very 

 poisonous, but others again have declared that it is per- 

 fectly harmless. One specimen sent to Sir John Lubbock 

 killed a frog in a few minutes and a guinea-pig in three 

 minutes. 



The conflicting statements are probably due to the fact 

 that the teeth are very small and easily removed. Some 

 specimens of the creature reach the length of three feet. 

 As experiments made by allowing the lizard to bite animals 

 are untrustworthy on account of the uncertainty of getting 

 the poison equally introduced into the tissues at every 

 bite, Doctors Weir Mitchell and Reichert collected the 

 saliva so as to be able to inject it in known quantities. 

 The saliva was obtained by making the animal bite on a 

 saucer-edge. It dropped in small quantities from the 

 lower jaw, and had a faint and not unpleasant aromatic 

 odour. It was distinctly alkaline, in contrast to serpent 

 venoms, which are all alike acid. Four and a half 

 minims of it diluted with half a cubic centimetre of 

 water and injected into the breast of a large pigeon 

 caused the bird to walk unsteadily after three minutes. 

 At the same time the respiration became rapid and short, 

 and at the fifth minute feeble. At the sixth minute the 

 bird fell in convulsions with dilated pupils, and was dead 

 before the end of the seventh minute. There was not 

 the least trace of any local effect of the poison, as there 

 would have been in the case of crotalus venom. The 

 muscles and nerves were perfectly sensitive to stimulation 

 mechanically or by weak induced currents. The heart 

 was arrested in complete diastole, and was full of firm, 

 black clots. The intestines looked congested. In an- 

 other experiment it was found that the poison gradually 



1 Tables on the system above described were first published in the year 

 1651, having been prepared by Mr. Reynolds, Assay Master at the Mint in 

 the Tower A second edition was afterwards issued with corrections and 

 additions in 1677. 



2 *' A Partial Study of the Poison of Heloderma suspectnm (Cope), the 

 Gila Monster." By Dr. S. We.r Mitchell and Dr. E. T. Reichert of 

 Philadelphia. 



lowered the arterial tension and rendered the pulse irre- 

 gular. Its action on the pulse is not due to any effect 

 upon the pneumogastric nerves, as it is just the same 

 when these nerves are cut. When applied to the heart of 

 a frog it arrests its pulsations in diastole, and the organ 

 afterwards contracts slowly — possibly in rapid rigor 

 mortis. The cardiac muscle loses its irritability ta 

 stimuli at the time it ceases to beat. The other muscles 

 and nerves respond readily to irritants, but the spinal 

 cord has its power annihilated abruptly and refuses to 

 respond to the most powerful electrical currents. 



The authors conclude that "this interesting and viru- 

 lent heart poison contrasts strongly with the venoms of 

 serpents, since they give rise to local hemorrhages, and 

 cause death chiefly through failure of the respiration and 

 not by the heart, unless given in overwhelming doses. 

 They lower muscle and nerve reactions, especially those 

 of the respiratory apparatus, but do not as a rule cause 

 extreme and abrupt loss of spinal power. Finally, they 

 give rise to a wide range of secondary pathological 

 appearances which are absent from Heloderma poi- 

 soning." 



This distinction between the action of the poison of 

 Heloderma and serpent venom is correct as far as regards 

 the poison of the rattlesnake and perhaps also the Cro- 

 talida; generally, but the distinction is by no means 

 marked between the poison of Heloderma and the venom 

 of the cobra. This venom was found by Sir Joseph 

 Fayrer and Dr. Lauder Brunton to have but a slight local 

 action as contrasted with that of the rattlesnake or of the 

 daboia, and to produce no local hemorrhage. The effect 

 of cobra poison on birds also is very much the same as 

 that of the Heloderma -, and in the experiments given in 

 this preliminary paper, the effect of the Heloderma 

 poison on the heart of the frog is very much like that of 

 cobra poison, the failure of action with subsequent and 

 gradually increasing contraction being almost precisely 

 the same. 1 



In Brunton and Fayrer' s experiments on cobra poison, 

 the fall of blood-pressure was less marked, but it still 

 occurred. Paralysis of the spinal cord also is produced 

 by cobra poison, and the experiments in this preliminary 

 paper are too few to enable us to decide whether the 

 paralysing effect is greater from the poison of Heloderma 

 than from cobra venom. We shall look with much 

 interest to the further study of the venom of this curious 

 animal, which the authors intend to make on the arrival 

 of the fresh specimens which they are about to receive. 



ON THE CONDENSATION OF VAPOUR FROM 

 THE FUMAROLES OF THE SOLFATARA OF 

 POZZUOLI 



T l HE fumaroles of the Solfatara of Pozzuoli, and 

 •*• especially the larger fumarole known as the Bocca 

 delta Solfatara, give a striking illustration of the action 

 of smoke in causing the condensation of aqueous vapour 

 in the manner demonstrated by the experiments of 

 Coulier, and more especially by those of Dr. Aitken. 



Persons who have visited the Solfatara will remember 

 that one of the feats by which the ciceroni of the place 

 try to excite the wonderment of visitors is to light 

 some paper or a few dry branches, and put the flaming 

 body before or inside the mouth of the principal fuma- 

 role, augmenting thus very greatly the volumes of cloudy 

 vapour escaping from the fissure. This phenomenon can 

 be observed in all volcanic fumaroles. A flame is not 

 indispensable, the condensation of the vapour being also 

 produced by the mere smouldering of tinder. 



Prof. Piria first tried to explain the phenomenon. He 

 thought that small quantities of sulphuretted hydrogen 

 issued from the soil together with the aqueous vapour : 



1 Brunton and Fayrer on the Poison of Indian Venomous Snakes (Rcy. 

 Soc. Proceedings, January 22, 1874, p. 126). 



