AX. 27, 1882.] 



• KNOWLEDGE • 



I If late the Xeio York Herald lias made some remarkable " liits." 



ill ■ stormy ctardcter of the past three mouths woiild permit them 



risk almost anything resemlilinf; a " weather-case " with a fair 



iMce of success. Nevertheless, they make some "very bad 



ts," and if they venture to add more to the simple announce- 



: int of a storm, such as "developing energy," "snow in the 



N >rth," " attended by electrical phenomena," &c., it betrays an 



I'tiinpt on the part of the "prophet" to obtain credit for an 



unt of .lagacity he does not possess. I shall not dwell upon the 



' ping character of these warnings generally, but draw tlie attoii- 



n of Mr. Spiller and A Fellow of the Eoyal Astronomical Society 



to the circumstance that up to the present time the Americans 



have not attempted to foretell fine harvest weather, or settled 



weather of any kind, which, if done, would cause me to view 



their weather predicting more favourablv. — Yours, &c., Alfbed 



DOXB.VTAXD. 



COMMUNICATION WITH THE MOON. 



[248]— The following e.\cerpt from the Edinbur{jh Nen- Phlio- 

 gophical Journal for October, 1826, muy interest " X. Davine," 

 (letter 206, p. 233). As the Editor has remarked, the idea is due 

 to a German, not a Frenchman. 



' Gmithuisen, in a conversation with the great astronomer Gauss, 

 after describing the regular figures he had discovered in the moon, 

 spoke of the possibility of a coiTespondenee with the inhabitants of 

 the moon. He brought, ho says, to Gauss's recollection, the idea 

 he had communicated many years ago to Zimmerman. Gauss 

 answered, that the plan of erecting a geometrical figure on the 

 plains of Siberia corresponded with his opinion, because, according 

 to his view, a correspondence with the inhabitants of the moon 

 qsold only be begun by means of such mathematical contemplations, 

 and ideas which we and they must have in common." 



Gruithuisen was one of the most painstaking and keen-visioned 

 selenographerg who ever lived, though the exuberance of his fancy 

 frequently led him astray. The work done by him in the earlier 

 part of the lorcscnt century is something marvellous, considering 

 the comparatively small instruments he employed. Many of his 

 drawings, &c., have been recently published for the first time in the 

 German periodical Siriiis, and are worthy of careful study. — 

 H. Sadler. 



A NEW COMPARISON OF POISONS. 



[2W]— " S. E. P.'s" (No. 172, p. 208) criticicm of my letter is 

 somewhat hierogh-phical, and at first rather puzzling. He savs 

 the allegation is, that li. ce. is three times as poisonous as ba. ce. 

 I am curious to know what li. ce. and ba. ce. meaii. 



" S. E. P." continues that li. ce. has 20 per cent, of metal, where 

 the citrate has probably much less than 7 per cent. ; so H. ce. can- 

 not be his formula for lithium citrate (Lij, Co, H3, O- 10% Li), nor 

 yet for lithium chloride (Li CI), which contains 16-4 per cent, of 

 metal. 



That some metals may bo very poisonous in one form of combi- 

 nation, and not in another is very trne, but it depends upon the 

 properties of the substance employed for combination. 



I think if anyone has mystified M. Hichet's plain proposition it is 

 '8. E. P.," for lithium as a metal is uou-poisonous. — I am, iSir, 



TEcnxiCAL Chemist. 



ANIMAL ier.s!/s VEGETABLE FOOD. 



[250] — If the following be worthy of a place in your pages, I 

 shall be glad if you will insert it, for it has struck me that in the 

 arguments that have been brought forward in Knowledge on this 

 subject, and those used by vegetarians generally in favour of their 

 aiystem, one thing has been lost sight ofj or disregarded — viz., the 

 provision and requirements of nature. 



If we go to the frigid zone, we find that practically vegetable 

 food is out of the question, for the simple reason that it cannot 

 grow in those sterile regions, amongst the snow and ice. The 

 inhabitants are therefore obliged to eat that which is provided in 

 abnndance — viz., animal food. 



We are told that the effect of the extreme dry cold to which the 

 inhabitants are exposed, is to produce a desire for the most stimu- 

 lating food that they can obtain ; that in such a climate bread is 

 not only not desired, but is comparatively impotent as an article of 

 diet ; that pure animal food, the fatter the better, is the only suste- 

 nance which maintains the tone of the system, and supplies the 

 degree of muscular energy necessary for the particular wants of 

 the locality. 



But if we turn our thoughts to the torrid zone, the state of things 



entirely reversed. There, the general use of animal food would 



be exceedingly difficult ; for, as your readers will doubtless be 

 aware, in a hot climate, animals, if not cooked immediately they 

 are killed, become tainted and unfit for food ; therefore, it can only 

 be used on special occasions, and vegetable food is, to all intents 

 and purposes, the only food in hot climates. 



Also in the tropical regions of the globe, where the fertility and 

 productiveness of the soil are so largely increased by the high 

 temperature, less labour stiffices for the raising of food ; less labonr 

 is also required to pro\nde habitation and raiment ; loss demand, 

 therefore, is made upon muscular energy, and, consequently, less 

 or no animal food is required to keep it np. 



If we take into consideration personal taste, we find that, on a 

 hot summer's day, nine persona out of ten would prefer a dish of 

 cold, stewed fruit with rice, to a joint of hot, cooked meat ; and in 

 the winter it would be just the reverse. 



It seems to me, then, the conclusion to be drawn from the above 

 facts i* that as ice (to bring the matter home), live in a temperate 

 latitude, between the two extremes, where a moderate amount of 

 musaular energy is required to provide food, clothing, and shelter, 

 our diet should consist of both animal and vegetable, with a pre- 

 dominance of the former in winter, and of the latter in summer. 



0. E. H. 



P.S. — Does the trichina exist in bacon, or only in pork in its un- 

 cured state ? 



TO.iiDS. 



[251]— On p. 202 of No. 10, for .Tan. 6, 1882, appears a para- 

 graph on the vitality of toads, in which it is said that M. Legrips 

 asserts that toads are inoffensive. 



In Professor du Boiz-Reymond's lectures on " Physiology," which 

 I had the pleasure to hear last summer in Berlin, he distinctly 

 stated that toads were jioisonous, and that they ejected the poison 

 when molested. If the poison reached the face, striking, for ex- 

 ample, the eye, it would be dangerous certainly to the eyesight ; if 

 not more. He declared tliat they have poison enough to kill a 

 small bird ; and that even when experimenting with the common 

 frog, he had learned through painful experience to keep his eyes 

 shut when seizing them; for on more than one occasion they had 

 spurted out poison which caused pain enough on striking his eye 

 to make one keep to the sofa for the afternoon, as he expressed it. 



If you would, through your appreciated paper, throw some light 

 on this contradiction, you would much oblige yours, &c., 



D. R. McC. 



SUNLIGHT OX FIRE. 



[252] — With regard to my query, " Effect of Sunlight on Fires" 

 (136), I am much obliged to " C. T. B." for his reply, giving, as 

 it does, I think, a right explanation of what I called attention to. 

 I would remind " Paugul " that contradiction is not explanation, 

 and that no good is gained by telling querists that the evidence 

 they quote is useless, and that their sup))ositions are absurd. As a 

 matter of fact, nine people out of ten that I have asked tell me 

 that they think that bright sunlight does interfere %rith the burn- 

 ing of an ordinary house fire, and that a cigar, unless con- 

 tinually puffed, will go out nnich sooner if the sun is shining on it, 

 than otherwise. I enclosed a query with 136 concerning the nature 

 of noises made by trains, but apparently it was not worth insertion. 



N. 



DARWINISM AND THE MICROSCOPE. 



[253]— I beg to offer a few observations upon Darwinism, 

 although drawn from a new source. The microscopic examination 

 of the blood corpuscles belonging to different classes of the 

 vertebrata. 



Now it is well known that these discs vary greatly in form, size, 

 and structure, not only in those classes themselves, but even in the 

 different species of the same class. Thus in birds, reptiles, and 

 fishes, they ale, as Dr. Carpenter in his "Animal Physiology" 

 observes, " much larger than in the Mammalia, their form is oval 

 instead of round, and instead of being depressed in the centre, 

 they bulge out on each side." In man, for example, their diameter 

 is, according to him, 1-3200 of an inch, and in other mammals it 

 varies from 1-4000 to 1-5000 of an inch, although in the musk deer 

 (Moschus javanicus), it is only about 1-12000 of an isch. In birds 

 their long diameter is from 1-700 to 1-2100 of an inch ; in reptiles 

 from 1-1000 to 1-1800 of an inch ; and in fishes the long diameter 

 of the blood discs is about 1-1900 to 1-2000 of an inch." It is 

 remarkable too that the smallest British mammal, the harvest- 

 mouEO has as large corpuscles as those of the horse, and that in 

 the common mouse they are even larger than in the horse or ox."* 



' " Henfrey's Micrographic Dictionary." 



