MISCELLANY. 



377 



the use of a stiff brush, with sand. Having 

 thus taken out of the pond, cleaned, and 

 returned again to the water, many hundred 

 fish, it was discovered that the labor was 

 in vain, for the parasites were so numer- 

 ous that soon the fishes were infested 

 again. The crustaceans plainly were hold- 

 ing their own. Mr. Buckland now cleared 

 away the mud in front of the pipe, so that 

 the fish might have a chance of rubbing off 

 their tormentors against the bottom. He 

 next conceived the idea of spreading a 

 quantity of gravel about the pipe. With 

 the aid of this and an abundant supply of 

 tresh water at a low temperature, the fish 

 were enabled to rid themselves of their 

 parasites easily, and, in the cooler water, 

 the latter did not find the conditions of life 

 so favorable. 



A Worm that the Sparrows refuse. 



We iecently noted the appearance in the 

 public parks and squares of Philadelphia 

 of a caterpillar which threatened to de- 

 stroy the the trees. The English sparrow 

 had effectually exterminated the measuring- 

 worm in those parks, but showed no dispo- 

 sition to attack this new destroyer of the 

 foliage. At the late meeting of the Ameri- 

 can Association, Dr. John L. Le Conte de- 

 scribed this insect as the larva of the moth 

 Orgyia leucostigma . It is a slender cater- 

 pillar, covered with stiff yellow-and-black 

 hairs. The sparrow does not attack it, 

 being deterred, probably, by the bristles, 

 by which it is protected. But, fortunately, 

 the nuisance can be abated without the 

 aid of the sparrows. When the caterpillar 

 has attained its full growth on the tree, it 

 crawls to a neighboring wall or fence, and 

 there, fixing its cocoon, undergoes trans- 

 formation. The remedy against the annoy- 

 ance is now very simple, viz., by sweeping 

 the cocoons from the walls and fences with 

 stiff brushes, and placing around the trees 

 rings of tin-plate inclined at an angle. This 

 will give the trees immunity, because the 

 insects are not provided with wings for 

 flight. 



A New Source of Illuminating Gas. 



An oil-bearing shale of considerable thick- 

 ness, called Kimmeridge coal, or clay, un- 

 derlies the whole county of Dorset, and is 



met with in other parts of England. Vari- 

 ous attempts have been made to utilize this 

 deposit for the purpose of producing light 

 and heat, but with little success hitherto. 

 Now, however, the Rev. Henry Moule has 

 succeeded in devising a method of produ- 

 cing from it a good, useful gas. The new 

 gas is obtained by the destructive distilla- 

 tion of the shale, the gaseous products being 

 submitted to purification before use. In 

 this latter process, as also at other stages 

 of the manufacture, chalk is used. The 

 gas itself, though not odorless, is by no 

 means so pungent nor so unpleasant as 

 ordinary coal-gas. During combustion no 

 odor is perceptible, and, so far as can at 

 present be ascertained, the products of 

 combustion contain no noxious gases. Be- 

 sides the gas, a pungent oil is produced, 

 which Mr. Moule believes can be rendered 

 comparatively odorless, and may with ad- 

 vantage be applied to various purposes. 

 The inventor also proposes to utilize the 

 heat-giving properties of shale and chalk 

 for heating, both by means of gas and in a 

 direct manner, his plans having been ma- 

 tured in this respect. 



Contagious Ophthalmia. In English 

 poor-houses and " pauper-schools," con- 

 tagious ophthalmia has, from the founda- 

 tion of such institutions, afflicted the in- 

 mates. It is produced by unsanitary con- 

 ditions of life want of cleanliness, over- 

 crowding, ill-ventilation, etc. It might be 

 supposed that these establishments would 

 have been greatly improved in later times, 

 owing to the increased attention now be- 

 stowed on public hygiene ; but the con- 

 trary is the fact, as we learn from a dis- 

 course by Dr. Brudenell Carter. A serious 

 charge is brought by this gentleman against 

 the Poor-Law Board, viz., that during the 

 last few years their unwisdom has developed 

 this malady in workhouses and pauper- 

 schools " in a manner to which previous 

 English experience affords no parallel." 

 The Government has refused to let the 

 truth be seen, but Dr. Carter has been able 

 to obtain, from a private source, a copy of 

 a report made to an official inspector by 

 the medical officer of one of the schools. 

 It states, among other curious matters, 

 that, of 1,062 children in the school in 



