PATENT SUBSTITUTE FOR LEATHER. 



and change, the order and harmony of the 

 whole remain unalterable. 



After a general view has been taken of 

 the nature of the elements, and of the 

 principles of chemical changes, the next 

 object will be the structure and constitu- 

 tion of plants. In all j)lants there exists 

 a system of tubes or vessel?, which in one 

 extremity terminate in roots, and at the 

 other in leaves. It is by the capillary 

 action of the roots that the fluid matter is 

 taken up from the soil. The sap in pass- 

 ing upwards becomes denser, and more 

 fitted to deposited solid matter: it is modi- 

 fied by exposure to heat, light, and air in 

 the leaves; descends through the bark; in 

 its progress produces new organized mat- 

 ter; and is thus in its vernal and autumnal 

 flow, the cause of the formation of nevV 

 parts, and of the more perfect evclution of 

 parts already formed. 



In this part of the inquiry, 1 ^tall en- 

 deavour to connect together in a general 

 view, the observations of the mostenlight- 



From Uie Philosopliical Magazine. 

 IODINE IN MINERAL WATERS. 



Dr. Cantu has proved the existence of 

 Iodine, in the state of hydriodate, in the 

 sulphurous mineral waters of Castelnouve 

 d'Asli. He infers, as a probability, from 

 his experiments, that iodine is a consti- 

 tuent part of all sulphurous waters which 

 contain muriates; and to this he attributes 

 the medical efllcacy of these waters in 

 diseases of the glandulnr and lymphatic 

 systems. {Giornale di Fisica.) — Dublin 

 Phil. Journ. 



Fi-om the same. 

 ACCOUNT OP PATENT SUBSTITUTE FOR 

 LEATHER, INV'ENTED BY MR. THOMAS 

 HANCOCK. 



In a former patent, Mr. Hancock pro- 

 posed to form a substitute for leather, by 

 depositing caoutchouc in a fluid state, 

 upon loose fibres of wool, cotton, or flax, 

 felted or matted together. In the present 

 patent, he uses a woven cloth, made of 



ened philosophers who have studied the i wool, cotton, or flax. When this cloth is 



physiology of vegetation 



Those of Grew, Malpighi, Sennebier, 

 Darwin, and above all, of Mr. Knight. 

 He is the latest inquirer into these inter- 

 esting subjects, and his labours have tended 



stretched upon a flat surface, the composi- 

 tion t ) be presently described is sjji-ead 

 over it. Above the composition, a uni- 

 form layer of wadding, made of cotton, 

 flax, wool, silk, or hair, is to be laid, and 



most to illustrate this part of the economy i the whole pressed between a pair of rollers, 

 of nature. i in order to force the fluitl composition 



The chemical composition of plants has . among the fibres. It is then to be dried 

 within the last ten 3'ears, been ehicidated 'at a temperature not exceeding 80° or 90° 

 by the experiments of a numbei' of chemi- 1 of Fahrenheit. 



cal philosophers, both in this and in other Mr. Hancock has given us the following 

 countries; and it forms a beautiful part of compositions to be used according to cir- 

 general chemistry; it is too extensive to 1 cumstances: 



be treatetl of minutely; but it will be ne- 1 First composition. Dissolve two 



cessary to dwell upon such parts of it as pounds of caoutchouc in one gallon of oil 

 afford practical inferences. | of turpentine and highly rectilied coal tar. 



If the organs of plants be submitted to \ Add six ounces of black resin, two pounds 

 chemical analysis, it is found that their i of strong glue size, and one pound of yel- 

 almost infinite diversity of form, depends | low ochre, whitening or powdered pum- 

 upon different arrangements and combina- 

 tions of a very few of the elements; sel- 

 dom more than seven or eisht belons; to 

 them, and three constitute the greatest 

 part of their organized matter; and ac- 

 cording to the manner in which these ele- 

 ments are disposed, arise the different pro- 

 perties of the products of vegetation, 

 whether employed as food, or for other 

 purposes and wants of life. 



( To be continued.) 



ice. 



Second cojnposition. — Dissolve 1 1-2 

 pounds of caoutchouc as before, and hav- 

 ing melted and mixed one pound of glue 

 size and i-esin in a steam bath, add the dis- 

 solved caoutchouc to it, stirrino; while 

 mixing them. The wb.ole must then be 

 strained through a sieve. 



The first of the above compositions 

 must be used when a cheap and stiff" sub- 

 stance is required, and the proportions 

 may be one-third whitening or glue; but 



