July 1, 1869.] 



HARDWICKE'S SCIENCE-GOSSIP. 



165 



More Light for Drawing— If "W. E. B.," 

 Swansea, will buy a Bockett lamp, or else have one 

 of the metal chimneys fitted on to an ordinary 

 parafine lamp, he will get all the light he requires. 

 But I fancy if he were to use Mr. Scantlebury's 

 plan he would get more light still, as the mirror 

 intensifies the light on the paper. I have found 

 that Mr. Scantlebury's is the most perfect method 

 for drawing ; but I have somewhat modified it, and 

 clone away with the expense his apparatus would 

 lie, by slipping off the mirror of my microscope and 

 fitting it by means of a wine-bottle cork on to the 

 stand of my condensing bull's-eye ; then I direct the 

 rays of light through the object bv means of one of 

 Collins' Bockett lamps— C. B.H. 



Microscopic Preparation. — ;"H. W." had 

 better procure "The Microscope in Medicine" by 

 Prof. L. Beale, where he will find all he requires 

 respecting both transparent and opaque injection, 

 treated at far greater length than the narrow limit of 

 a reply in Science-Gossip would permit. The pro- 

 bable cost at a second-hand book-shop would be 

 about five shillings. — /. W. G. 



The Blood.— Mr. Scott's difficulty relative to 

 the white corpuscles of the blood probably depends 

 on the term white as applied to them. The more 

 applicable term is colourless. A high authority 

 states the relative proportions of the globules in the 

 blood of the higher mammalia, to be one colourless 

 to two or three hundred coloured. In man, 

 however, we have reason to believe the colourless 

 exist in far greater proportions. A case of anaemia 

 (where the red are deficient in quantity) or of 

 Leucocythcemia (where the colourless are actually, 

 and not merely relatively, increased in quantity), 

 will at once, by microscopic examination, satisfy 

 Mr. Scott that these corpuscles really exist. For 

 their detection he should rely on the following dis- 

 tinctive features : — 



Colourless. Red. 



Sate) f ™ th of au iuch - ^ th of an inch - 

 Form — Spherical. Biconcave, flattened discs. 



Cedents- {HSSaS} OMMbt 



The red have a great tendency to adhere in rouleaux ; 

 hence, the colourless remain more or less isolated. 

 The effects of osmosis may be readily remedied by 

 employing a medium such as glycerine diluted to 

 the same sp. gr. as that of Hsematoglobuline. — 

 W. Bevan Lewis, L.R.C.P. (Loud.). 



Preservation of Insects. — If Mr. Alfred Allen, 

 instead of dipping his moths in benzole, will try the 

 following recipe, he will find that no insect what- 

 ever will touch them. Dissolve corrosive sublimate 

 in spirits of wine, adding the sublimate until a 

 whitish deposit is formed upon a black feather 

 dipped in the solution ; then add about one-sixth 

 more spirits ; dip the moths in this, then drain off 

 the fluid from the wings, and let them stand in a 

 thorough draught to dry. — C. B. II. 



Boiled Lobsters.— Perhaps some of your 

 readers can tell me why lobsters and prawns change 

 colour when boiled. — F. G. Mountford. 



Management op Leeches. — You have had two 

 or three paragraphs upon this subject. Years ago I 

 used to have a good deal to do with them, and no 

 way of treating them is more successful than, when 



they are taken off a patient, to put them on a plate 

 with some brown sugar ; where they are left a short 

 time and then washed. I have repeatedly re-used 

 them in the course of a quarter of an hour or so. 

 The keeping of them depends almost entirely in 

 constant change of water, and well washing them 

 from the skin or slime they throw off. — E. T. S. 



Suspended Moles.—" The mole-catchers are in 

 the habit of suspending their victims on branches, 

 mostly those of the willow, or similar trees ; but 

 their object I never could make out, nor could they 

 give me any reason, except that it was the custom." — 

 (Wood's " Common Objects of the Country," p. 25.) 

 The object the mole-catchers have in view is plain 

 enough. They wish to let their employers see that 

 they are attending to their duties, and attending 

 to them successfully. In order to do this they sus- 

 pend their victims in some public place on the farm, 

 or in the village. In this neighbourhood the mole- 

 catchers are in the habit of emptying their baskets 

 by the roadsides in some public part of the village, 

 where they can be easily seen. I have frequently 

 seen them, and smelt them too. I have counted 

 thirty in a heap. — /. Ranson, York. 



Vegetable Haiks. — Those interested in the 

 hail's of plants as microscopic objects will find 

 beautiful stellate examples on the under side of the 

 leaves, and on the stems of Aralia papyri/era, the 

 Chinese rice-paper plant, fine specimens of which 

 may be seen in the Subtropical Gardens at Battersea 

 Park. I have a small quantity of the leaf, and shall 

 be glad to send some to any of your correspondents 

 on receipt of address and stamps to cover postage. 

 I have also a small quantity of pollen of Cobea 

 scandens, and a few mounted slides of same for ex- 

 change. — </. Carpenter, Waltham Cross, Herts. 



Death op a Tortoise.— In the early spring I 

 bought a good-sized tortoise of the common sort, 

 and turned it loose in a small walled garden. At 

 first it seemed to eat nothing ; but as its summer 

 appetite began to awake, we gave it lettuce and cab- 

 bage-leaves. A few days ago it was found on a flower- 

 bed, between a scarlet geranium and the brick wall, 

 witli a greenish slimy froth issuing from its jaws, 

 which it endeavoured to rub away with its fore-legs. 

 It opened its mouth at intervals, and made a click- 

 ing or gasping sound, and finally it pushed itself 

 violently against the wall, vomited a quantity of 

 greenish slime, and when visited a few hours later, 

 at was found dead and stiff. I was away from home 

 the time myself, but my two sons, who reported the 

 circumstance to me, came to the conclusion that it had 

 poisoned itself by eating unwholesome food. We 

 examined the scarlet geranium, but found no signs 

 of its leaves having been bitten. — F. T.Mott, Leicester. 



Bryopsis. — "M. D." has proved Bryopsis to be 

 one of the best seaweeds for an aquarium, but is 

 now out of it, and wishes to know where it can 

 be procured in London. 



Why do Insects Ely to the Light?— On 

 reading "W. H.'s" article in Science-Gossip for 

 June, I took a light and held it near an aquarium 

 containing Water-scorpions, Notonecta, and Newts 

 — very few of which are vegetarians. The two 

 former were instantly struggling against the side of 

 the glass towards the light, and in the course of 

 less than a minute, several of the newts were with 

 them. A fanner tells me that he has frequently 

 known owls and night-jars fly against the windows 

 of a lighted room. — J, G. Odell. 



