HARDWICKE'S SCIENCE-GOSSIP. 



20I 



English language will at once become the medium 

 of communication between all the nations. In every 

 other respect but its vile spelling, our tongue stands 

 pre-eminent as the simplest and best that human 

 beings have spoken, and, besides this, it has now such 

 a start in the race for universality that it is certainly 

 destined when orthographically purified, todebabelize 

 the world. 



A Sensational Cure.— Many of my readers 

 have probably read the paragraph that has appeared 

 in many newspapers narrating the wonderful cure of 

 a blind man by a flash of lightning. The " British 

 Medical Journal " disposes of the marvel by a simple 

 sifting of the facts. The man was injured by an 

 explosion in a mine ; one eye was totally destroyed, 

 and he became unable to see with the other. He 

 was in hospital for seven weeks with fits, and on 

 leaving was led about, owing to his defective sight. 

 One evening after a flash of lightning he noticed that 

 he " could see indistinctly objects near to him." A 

 few days after he could walk about without a guide. 

 On enquiry, the editor of the journal learned that for 

 some time after this the patient could only partially 

 open one eye, that the cornea was opaque, and had 

 been gradually clearing for many months past, and 

 adds, that in the absence of any authoritative state- 

 ment as to the condition of the vision before and 

 after the lightning flash, there seems no reason for 

 assuming that the case was anything but an ordinary 

 one in which the cornea was slowly clearing. 

 Nothing is more common than for a gradual improve- 

 ment to be suddenly noticed when it has reached a 

 certain stage. 



Imperfect Combustion. — All who have experi- 

 ence in the use of mineral oil lamps must sooner or later 

 learn that the condition demanded for their burning 

 without smell is that the wick shall be turned up so as 

 to obtain a full-sized flame without actual smoking. 

 It is commonly supposed, at first, that by keeping the 

 flame low all objectionable odour is prevented, but 

 the contrary is the case. Something more may be 

 learned, by first charging a lamp with a measured 

 quantity of oil burning it with the flame at full size 

 for a given time and ascertaining the loss of oil ; then 

 making a second experiment with the same lamp, 

 same quantity of oil burning the same time, but with 

 wick turned down so as to have but a fraction of the 

 amount of light supplied during the first experiment. 

 On measuring the loss of oil this time it will be found 

 but little less than in the first case. Therefore in 

 turning down such lamp flames we obtain no such 

 saving of material as in turning down a gas flame. 



The reason is that with the low flame a considerable 

 quantity of the products of incomplete combustion are 

 making their escape into the air, and these are not 

 only offensive to the sense of smell, but are also 

 injurious to health, they are analogous to the vapours 



that are created by blowing out the flame of a tallow 

 candle and leaving the wick to smoulder. 



M. N. Grebant has recently studied the action of 

 the much milder products of the imperfect combustion 

 of coal gas, by placing a dog in a chamber of twelve 

 metres' capacity in company with an ill-supplied 

 Bunsen burner. A comparison of the gases of the 

 blood taken from the carotid artery, before and after 

 the experiment, showed that the oxygen of the 

 original blood was almost wholly displaced by 

 carbonic oxide. 



Exhaustion of Soils. — The virgin soils of 

 Australia are suffering a form of exhaustion due to 

 the loss of nitrogen. Mr. R. W. E. Macivor has 

 written on the subject in " The Chemical News," 

 vol. 57, p. 25, pointing out the causes of this, one of 

 them being the practice of burning the straw instead 

 of returning it to the soil as we do after it has done 

 its work as litter for cattle and horses. I refer 

 particularly to this, as such wastefulness is not 

 peculiar to Australia. Ignorant gardeners and 

 ignorant farmers burn the weeds they remove from 

 the soil, and in doing so cast all the ammonia they 

 contain into the air, and then purchase guano 

 imported from the other side of the world to replace 

 the loss. If these weeds were properly stacked and 

 sufficiently rotted to destroy the fertility of their seeds, 

 they would, when returned to the soil, constitute the 

 best of all possible manures, because they return to 

 the soil just what they have taken from it. 



In ordinary gardens the crop of weeds far exceeds 

 in exhaustive energy the sum total of all the other 

 crops. In flower gardens this excess may amount to 

 ten or a hundredfold, and yet many gardeners are 

 deliberately guilty of the heinous offence of carting 

 away the weeds bodily, which is still worse than 

 burning them, as in the latter case the ash, with its 

 mineral salts may be returned. It is not always 

 ignorance that induces this wasteful proceeding. I 

 have noted the doings of more than one gardener who 

 has a small nursery of his own, and who also attends 

 to the gardens of villa residents in the neighbourhood. 

 I found that most of these studiously throw away the 

 weeds from the gardens of their employers, and 

 religiously save their own. They commonly make a 

 profit on the stable manure which they purchase for 

 the purpose of compensating the unreplaced ex- 

 haustion of the outcast weeds. In some cases, of 

 course, the employer not the gardener, is the culprit, 

 the latter merely obeying orders, or the garden in 

 question may be a little back yard all too close to the 

 house to allow space for a weed heap. In every case 

 the waste is shameful, and only mitigated by the fact 

 that somebody else may appropriate the castaway 

 weeds and use them properly, and in the case of 

 burning that some of the ammonia may be washed 

 from the air by rain to improve the crops of more 

 deserving agriculturists. 



