26fi Htpurt of Chemistry and Expariinental Philosophy. [April 1, 



its west ni.titr'in, by ii river they call 

 Murnim-liiil-gee. The lake runs from 

 N. to S. about ;50 miles, ami extends 



in breadth from two to ten miles, its 

 mart;iii abuiinding in the most pictur- 

 esque bays and points." 



REPORT OF CHEMISTRY AND EXPERIMENTAL PHILOSOPHY. 



TN the district of Loiulon, west of Tot- 

 tenham Court Roati, a very improved 

 kind of street-lamps have been introduced, 

 which in whiteness and intensity of their 

 li}?ht,far exceed the street ^s-lights, under 

 the same bulks of flame ; and each of these 

 lamps beinir independeut, there is no dan- 

 ger of a whole district being- left in dark- 

 ness at once, through an accidental or de- 

 sipncd stoppaire or destruction of the ejas 

 main; nor are the inhabitants burthened by 

 any expense of service-pipes, and the many 

 et icteriiti of that mode of lightinp:. These 

 lamps have been supplied by Major Coch- 

 rane, under two patents, one for the mode 

 of dislillinijai.d nianag'ing' the essential oil 

 of tar, and the other for the construction of 

 a lump for burning: this pellucid and very 

 volatile and inflammable oil, closely resem- 

 bling-, if not identically the same, with puri- 

 tied naptfia : — which oil, in its e^reatest 

 jieifection, is prepared in Scotland, at once 

 from the coals. The essential oil, prepared 

 from this p^as-work tar, is found, especially 

 when the wicks of the lamps are trimmed 

 the least too higrh, to deposit carbon on the 

 wcks, which the Scotch oil never does, 

 and in such cases occasions lamps to smoke, 

 and sometimes, owins: to the very pfreat vo- 

 latility of the g^as-work oil, a smoking lamp 

 has been filled with explosive vapour, 

 which has taken fire and destroyed the 

 lamp-glass : accidents which have never 

 happened with the use of the Scotch oil. 

 From the facility of preparing this oil at 

 any colliery, and in any quantity, and from 

 the cheapness tf its conveyance to town by 

 ■canals, we anticipate that this improved 

 mode of lighting our streets and roads will 

 become very general, 

 'i Luke Howard, Esq. has addressed a 

 •letter to Mr. Tillpch, on the best means for 

 conducting meteorological observations in 

 ditTerent places and climates, so as to pro- 

 duce some uniformity in the modes of ob- 

 taining and summing up the results. 



The mcicorolor/ical year to begin with 

 the vernal equinox : by this means, the six 

 summer months are made to form the first 

 division, and the six winter months the se- 

 cond ; for the purpose doubtless, though he 

 does not mention it, of contrast hig the 

 mean temperature, rain, &c. of the two sea- 

 sons ; and of each of thcra with the same in 

 other years. 



The subdiviiions to be of /en days each. 

 The author thinks a mean result founded 

 ou the month comjircheuds too ntany of the 

 daily observations, and that of the ueck too 

 fcr. ; vihilc result* taken ou cxerr tCii riavs 



would, in his opinion, give the course of 

 temperature, in particular, in a more per- 

 spicuous manner. Each of the four sea.fons 

 in this case would consist (with the neces- 

 sary intercalary additions) of nine decade* 

 of days. And he recommends the use of 

 ciirxex for the purpose of expressing every 

 thing in meteorology that is subject to 

 measures. Tliis would do away at once 

 with so much difliculty, as to render it easy 

 to proceed in common with our respective 

 observations, and compare them in detail, 

 as well as in result, at a glance ; at least 

 until the great object of an uniform measure 

 for all civilized nations be satisfactorily ac- 

 complished. The data in figures should, 

 however, says he, in this case be required 

 along with the graphical representations, 

 or should at least be kept in readiness to be 

 produced as vouchers of their accuracy. 



Dr. Andrew Ure, Professor in the An- 

 dersonian Institution, Glasgow, in his new 

 edition of Nicholson's Chemistry, has pub- 

 lished the following summary of the doc- 

 trine of Chemical Equivalents. This is a 

 term introduced to express the system of 

 definite ratios, in which the corpuscular sub- 

 jects of this science reciprocally combine, 

 as referred to a common standard, reckoned 

 unity. Thus, if we assume oxygen as the 

 standard, from its almost universal relations 

 to chemical matter, then calling it unity, 

 we have, in the following examples, these 

 ratios reduced to their lowest terms, in 

 which the equivalents vvill be prime ratios. 

 Tl>e lowest ratio, or equivalent prime of 

 oxygen being 1-000. 



Hydrogen will be - 0-125 

 Fluor? - - 0-375 



Carbon - - 0-750 



Phosphorus - - 0-500 



Azote - - 1.750 



Sulphur - - 2.000 



Calcium - - 2-550 



Sodium - - 2-fl.50 



Potassium - - 4-950 



Copper - - 8-00 



Barium - - 8-75 



Lead - - 13-00 



The substances in the above table, sus- 

 ceptible of reciprocal saturation, can com- 

 bine with oxygen or with each other, not 

 only in proportions corresponding to these 

 numbers, but also frequently in multiple or 

 submaltiple proportions. We have there- 

 fore two distinct propositions on this inte- 

 resting subject. 



Ist, The general reciprocity of the satu- 

 rating proportiosis. 



•Jd, The multiple and submultiplc pro- 

 portions 



