August 11, 1893. 



SCIENCE. 



99 



In order to be sure that I had rightly identified the two 

 forms, I sent specimens to Professor Eiley. He at once 

 replied: "You are j)erfectly correct. A. [this refers to 

 the lettering of the specimens] is the form which I des- 

 cribed as Fulvinaria maclurae, while h. is identical with 

 typical specimens of Pulvinar-ia innunierabilis on maple." 



It appears that Kobert Kennicott was the first to sug- 

 gest the name maclurae, and Fitch to publish it. This 

 was in the Country Gentleman, Jan. 18, 1855. In 1868 

 Messrs. Walsh and Kiley jjublished another description of 

 the osage orange scale, also using the name maclurae. 

 Those who do not consider the Country Gentleman a 

 prox^er medium for scientific description may cite Y/alsh 

 and Riley as nomenclators. If this should be done, it 

 would seem that innumerahilis Eathv., published in the 

 Pennsylvania Farm Journal, 1854, has at least no better 

 standing, in which case Fitch's name acericorticis, given in 

 the Tram. K Y. Agric. Society, 1860, should be employed, 

 or if it be insisted that the descrij)tion must appear in a 

 purely scientific publication, we must fall back on aceri- 

 cola, Walsh and Riley, 1868 ! For my own part, I would 

 use the earliest name in each case. Tout one must allow 

 that this is a matter for legitimate differences of ox^inion. 



Thus we have — 

 (1.) Fulvinaria innumerahilis, Eathv., 1854. The Cottony 

 Scale of the Maple. 

 = acericorticis. Fitch, 1860. 

 = acericola, W. & E., 1868. 

 (2.) Fulvinaria maclurae, Kenn. MS., Fitch, 1855. The 

 Cottony Scale of the Osage Orange. 

 = maclurae, W. & R, 1868. 



It need hardly be pointed out that the se]Daration of 

 these races or s^Decies is a matter of some interest to 

 economic entomologists. T. D. A. Cockeeell, 



Las Cruces, N. Mex., July zg, 1893. 



Explosive Gas in Hot Water Apparatus. 



In the hot water apparatus, used in heating houses, it 

 is well known that gas or "air" accumulates from time to 

 time. This is let off from the radiators where it may col- 

 lect by turning the "air" tap provided; otherwise the ac- 

 cumulation under ordinary circumstances would interfere 

 with the circulation of water through the pipes. Being 

 curious as to the nature of this gas, on a certain occasion 

 I smelled it when escaping from the tap, and detected a 

 peculiar odor of what I took to be a hydrocarbon com- 

 pound. Collecting some of the gas, I cautiously applied 

 a light to it, which produced an explosion. 



The furnace was a small, ujjright one, with the water 

 heated between its double walls, large enough to warm 

 in winter time a house of seven or eight ordinary rooms. 

 Anthracite coal was used. 



With a larger upright furnace, having tubes for the 

 smoke and heated gases to pass through in its upper part, 

 in addition to the water-filled sides of the first, the 

 amount of gas collecting in the highest radiator in the 

 house was more abundant, especially when anthracite was 

 used instead of bitumenous coal, for which the furnace 

 was also adapted. As a matter of fact, several litres of 

 gas were produced each week in two neighboring houses 

 supplied with this latter style of furnace, during the 

 j)eriod of observation, — a few weeks during last winter. 



A considerable quantity of the gas was collected for 

 demonstration before a popular meeting of the Institute 

 of Science. Jars of various sizes were filled with the gas, 

 which was burned under various conditions. 1st — The 

 peculiar odor of the gas was tested. 2nd — It burned in 

 the jars when inverted, and otherwise very much like 

 pure hydi-ogen, giving forth very little light, but much 

 heat. 3rd — The products of combustion showed no trace 



of carbonic dioxide which could be detected by the lime 

 water test, which was sensitive enough to detect its pres- 

 ence in the room from the resjairation of those present. 

 From this it was inferred that neither carbon monoxide 

 nor a hydrocarbon coiild be present in any considerable 

 quantity. 4th — Pure nitrogen dioxide injected into the 

 gas gave no ruddy discoloration. Hence, there was no 

 oxygen in the gas. 5th — ^T\^hen mixed with air it would 

 explode like air and hydi'ogen. 6th — It was not conven- 

 ient at the time to apply any other tests, or any very ac- 

 curate ones. The impression was formed that the gas 

 must be nearly pure hydrogen. 



If it was nearly pure hydrogen it must have come from 

 the decomposition of the v/ater, which would apparently 

 imply a corresponding oxidation of the ii-on piping or of 

 the heated iron in contact with the water within the fur- 

 nace. The greater abundance of the gas when anthracite 

 was used suggested that the origin of the gas was the 

 rapid oxidation of the water tubing within the furnace 

 when the heat was particularly intense. If so, every litre 

 of hydrogen produced would mean the conversion of over 

 one and a half grains of metallic iron into "rust." 



Again, if a lighted match should be applied to the tap 

 when this gas (j)ure) is being allowed to escape, the jet 

 would catch fire and "roar" with a hot, bluish flame, of 

 dimensions as terrific as the bore of the tap would allow. 

 As by the "boiling over" of the furnace the small tank 

 and upjjer coils under some conditions of water pressure 

 may be emptied and filled with air, what would the con- 

 seqviences be were the mixed gases allowed to escape at 

 night with a lamp held in the hand carelessly near such a 

 jet? 



The discussion of these demonstrations revealed the 

 fact that no one present ever knew or heard that the gas 

 escaping from radiators might be explosive — not even the 

 builders, plumbers and founders. 



Query 1. Is the formation of explosive gas within the 

 hot water apparatus of our houses rare, peculiar to cer- 

 tain furnaces, or is it common ? 



Query 2. Has an accurate analysis of such " gas been 

 made ; and if so, what are its constituents ? 



A. H. ]\IacK.\y, 



Halifax, N. S. 



Mineral Wax. 



In Science of July 14th, page 25, I notice an article on 

 "Mineral Wax," from which the following is an extract: 

 "In the United States it (mineral wax) is mined in situ at 

 Soldiers' Summit, Uintah County, and in Emery County, 

 Utah." Permit me to state that Soldiers' Summit of this Ter- 

 ritory is in Utah County ; that mineral wax or ozocerite is 

 not mined at Soldiers' Summit, nor in Uintah County, nor 

 in Emery County, Utah. I greatly regret to have thus to 

 correct the writer of the aforesaid article, for it would be 

 an especial pleasure to me to be able to report mines and 

 mining of ozocerite from Utah. I think a small quantity 

 of it occurs in Emery County. But it is not yet mined. Of 

 course, it may occur in large quantity in Utah, but u^d to 

 the jjresent time no satisfactory evidence of such occur- 

 rence has been jjresented. ' It is, however, possible at 

 present to report ample and satisfactory evidence of the 

 occurrence in Utah of large qiiantities of three related 

 hydro-carbons, viz.: ■wurlzillite, uintaliite and a.<phaltum. Of 

 these, the first has not yet been mined; but the second 

 and third are being mined with some degree of activity. 



Uintahite, often called Gilsonite, after a resident pros- 

 pector and miner in this vicinity, yields lilack varnish. It 

 is very light, being only a little heavier than water. Its 

 color is black, and its streak is brown or reddish-bro'mi. 

 It possesses a brilliant, shiny lustre, and has a -periect 

 conchoidal fracture, like that of glass, quartz and obsid- 



