78 



{HA RD WICKE 'S S CIENCE - G O SSIP. 



as well in the East Indies. The fruit is very large, 

 but the pulp is not so much relished as any of the 

 other kinds. The Cherimoyer of Peru is produced 

 by A. Cherimolia. The fruit is somewhat heart- 

 shaped, and scaly externally ; much esteemed by the 

 natives — nay, thought by the Creoles to be superior to 

 any other fruit in the world, but not so by Europeans, 

 although we have heard Europeans greatly admiring 

 the fruit, and have brought home seeds as relics 

 of remembrance. Specimens presei-ved in spirit may 

 be seen at the Kev^' Museum. 



Gocculus indicus.- — This term is applied to the fruit 

 ©f Anamirta Cocculus, a plant belonging to the 

 family Menispermacea:, most of which are climber^i. 

 The name applied to this drag would lead to the 

 conclusion that it was obtained from the genus 

 Cocculus. It must, however, be borne in miiid, that 

 such is not the case. It was formerly included in 

 that genus, but has since been separated and esta- 

 blished as a distinct genus ; the characters, in fact, 

 admit of such a rank. 



The characters of tlie genus Cocculus are thus : 

 flowers unisexual, the male flowers with six sepals, 

 six petals, and three stamens ; the female flowers 

 with three ovaries placed on a short stalk. The 

 genus Animirta has unisexual, dioecious flowers, 

 with six sepals but no petals. The male flowers 

 have numerous stamens united into one bundle 

 (monadelphous) ; the female flowers with three 

 ovaries attached to a thick receptacle. 



The plant is a native of the East Indies, growing 

 especially in Malabar and the Eastern Archipelago, 

 from whence the supply of this countiy is obtained. 

 It is a climbing plant with a light-coloured bark. 

 Leaves cordate, smooth, light green, paler beneath ; 

 flowers pendulous ; fruit slightly ovate, somewhat 

 lai^er than a 'full-sized pea, dark brown externally, 

 wrinkled, containing a yellowish, oily, kidney-shaped 

 seed. The quality of this substance is extremely 

 acrid, poisonous, and intoxicating ; its legal uses are 

 not very important, while no doubt the illegal uses to 

 which it is applied are otherwise. An ointment, 

 which was formerly more used than at the present 

 time, is obtained from it. It is also used for taking 

 fish. But the amount annually imported far exceeds 

 what is required for legal purposes. Where does 

 the superfluous portion find a home ? It is said that 

 the extract is very largely used for the adulteration of 

 porter ; and of course the result of such adulteration 

 is to produce giddiness and intoxication ; and it is to 

 such wholesale system of adulteration that the many 

 ills which are often heaped upon " malt liquor" may 

 be attributed. The poisonous nature of this drug is 

 due to the pi'esence of a chemical substance known 

 as " picrotoxin." This plant is figured in Wallich's 

 •'Asiat. Res.," vol. xiii. PI. 15, 16; or, what is 

 more desirable, the plant itself may be seen growing 

 in more than one place in the Royal Gardens, 

 Kew. 



THE MICROSCOPE IN GEOLOGY. 



THE annual address of the President of the Royal 

 Microscopical Society (H. C. Sorby, F.R.S., 

 &c.) for the present year, will, I fear, scarcely meet 

 with the unqualified approval of the "Microscopist." 

 It contains no hints about "pretty objects," &c. ; 

 but, for those who look upon the microscope as an 

 invaluable instrament of research, it will be read with 

 much interest. Unlike the usual addresses, it does 

 not contain a rc'snme of the work done with the 

 microscope during the past year. It might be fairly 

 called a lecture on the microscopic stracturc of rocks, 

 as the following outline of its contents will show : — 

 The application of the Microscope to Geology ; 

 Structure of Stratified Rocks ; Preparation and 

 mounting of the objects ; Object-glasses used. On 

 the Microscopical Characters of Sands and Clays : — 

 Origin of the IMaterial, viz. : Quartz, Mica, Horn- 

 blende and Schorl, Felspars, Pumice, Iron oxides, 

 Sorting the material. Pi-actical application of above 

 described : General Principles ; Identification of the 

 constituent materials ; Application of similar prin- 

 ciples to the sections of Rocks ; Application of the 

 above to special cases, viz. : — Millstone-grit of South 

 Yorkshire ; Sand of Egyptian Desert ; Sand derived 

 from Schists, Clays, &c. ; Volcanic Ash-beds in 

 British Strata. Conclusion. 



The author, after alluding to the labours of " our 

 late distinguished Honorary Fellow, Dr. Ehrenberg," 

 in the study of the organic constituents of rocks 

 remarks that very little has been done in the applica- 

 tion of the microscope to the investigation of the 

 nature and origin of loose and unconsolidated sands 

 and clays. . . . Seeing that this great subject had 

 hitherto been so much neglected, and is yet the very 

 foundation of our knowledge of the history of those 

 rocks which constitute a large portion of the accessible 

 framework of our globe, it appears desirable in my 

 address this evening to treat this subject in a syste- 

 matic manner. 



The study of the microscopical structure of strati- 

 fied rocks is very naturally divisible into two very 

 distinct questions, \'iz., the nature and origin of the 

 materials deposited, and the changes which have 

 occurred since deposition, but on the present occasion 

 I must almost entirely confine myself to the former. 



When the stratified rocks are sufficiently hard to 

 allow of their sections to be made, many facts may 

 be better seen in slices cut perpendicular to the 

 stratification, than by attempting to disintegrate the 

 rock and examine the detached particles. If the 

 particles are lield together by calcic or ferrous oxide, 

 or by any of the oxides of lime, they may be set free 

 by the action of cold dilute hydrocliloric acid, or by 

 a stronger hot solution, or if not reducible by these 

 means a small stiff brush may be used ; but violent 

 mechanical separation by crushing must be avoided. 

 When the particles are separated they should be 



