November 24, 1S93.] 



SCIENCE. 



S85 



out leaving a residue of charcoal or coke, while in nature, 

 according to Dr. Engler, we have no connection between 

 doposits of coal and the occurrence of petroleum. Another 

 theory, defended by Whitney, Hunt, Hofer and others, 

 ascribes the origin of petroleum to animal remains. To 

 test this latter theory, Dr. Eugler has conducted a series 

 of experiments so successful as to demonstrate clearly its 

 possibility, at least, if not its i^robability, from a chemical 

 point of view. First, some thousands of salt-water fishes 

 were distilled under strong pressure, with the production 

 of a liquid containing nitrogenous bases such as pyridin, 

 but having no similarity to petroleum. Recalling experi- 

 ments of Wetherill and Gregory as to the nature of so- 

 called "adipocere," the idea was conceived that possibly 

 in nature the nitrogenated animal substances were de- 

 stroyed and the fatty residue converted into petroleum. 

 Animal fat (train oil) was submitted to distillation under 

 a pressure of 25 atmosj)heres at a moderate heat of 300°- 

 400*, and it was found that 70 per cent (or 90 per cent 

 of the theoretical) of the train oil was transformed into 

 petroleum. The same results were obtained from the 

 other fats like butter, hog fat, artificial fats, the free, fatty 

 acids, etc. Not only illuminating oils were obtained, but 

 also the lighter hydro-carbons, gasoline, ligwin, benzine, 

 etc., and in those parts of the crude oil which show a high 

 boiling point were found and separated paraf&n wax and 

 lubricating oils. "As a matter of fact," says Dr. Engler, 

 "I have found in the distillate obtained by decomposition 

 of train oil nearly all of the constituents which have been 

 separated from the natural crude petroleum, and even the 

 gases, which, like natural gas, consist essentially of marsh 

 gas." For the chemism of the formation of the hydro-carbons, 

 Dr. Engler refers to a recent paper in the Bei'ichte der 

 Deutschen Chemischer Gesellschajt. 



EETICULATION OF SPINDLE-CELLED SAECOMA. 



BY A. COWLEY MAXLY, MIINSLOW, ENC LAND. 



No subject lends itself more freely to errors of inter- 

 pretation than the description of the microscopical ap- 

 pearances presented by histological and pathological 

 preparations. 



Even the delineation, both manual and photographic, of 

 the structure of the Diatomacese bear some semblance of 

 uniformity in the descriptions of different observers. 

 Still, to quote Dallinger, "In the present state of the 

 theory and practice of microscopy, it would be extremely 

 unwise to give absolute adhesion to what is now held, by 

 some students of diatom structure of no mean repute and 

 of unrivalled manipulative skill, to be the absolute struc- 

 ture of some of the larger forms." 



The same observation applies with still more force to 

 the former investigations, as it is impossible to compare 

 and correllate either the methods of preparation, observa- 

 tion or interpretation of different observers. They all 

 differ, as a rule, in some detail, and in addition there is 

 not only a marked tendency on the part of histologists 

 and pathologists to copj- the methods, drawings and re- 

 sults of others, but also a great liability to subjective 

 imitation through suggestion. 



Before confining myself to the evidences of reticulation 

 in sarcomal structures, I may mention that the appearance 

 in Polymyxa, so iuterj)reted, is perfectly evident in some 

 individuals and absolutely imiDerceptible in others. When 

 seen, it is extremely evanescent, and, therefore, can scarce- 

 ly be looked upon as evidence of the existence of formed 

 material, but rather as the effect of some temporary chem- 

 ical or physical change in or ujjon the external surface of 

 the protoplasmic mass. The same or very similar appear- 

 ances may be observed in Volvox, which are equally 

 erratic, but as they are unquestionably received as the 



evidence of formed material, the foregoing statement is 

 put forward as only a conditional hypothesis. 



The portion of the tumor from which the accompany- 

 ing sketch is taken was placed in Muller's fluid twelve 

 hours before the sections were cut. These sections were 

 taken from the central portion, where the fluid had evi- 

 dently no time to act, then slightly stained with carmine, 

 mounted in balsam and in the usual way. On being ex- 

 amined the same evening with a one-sixteenth water im- 

 mersion and No. 12 compensating eyepiece, it was found 

 that the markings forming portions of the reticulations 

 took a definite direction, that is, obliquely lateral to the 

 long diameter of the cell. This lateral obliquity did not 

 change on revolution of the stage, and therefore cannot 

 be interpreted as the result of oblique illumination. In 

 many of the cells a granular nebular nucleus was ob- 

 served, connected by slender and almost phantom 

 branches with the oblique lateral markings. At the junc- 

 tion of these branches with the nucleus their point of 



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S.-njJ* c^ll 



insertion or outgrowth, as the case may be, seemed to be 

 placed in the hyaline substance surrounding the gran- 

 ules, and unconnected with the granules themselves. 

 This latter observation is not laid down as an established 

 fact, but simply as something more than ordinary conjec- 

 ture. At the points of junction with the lateral markings 

 there seemed to be definite nodal enlargements increasing 

 in frequency towards the edges of the cell, and the whole 

 section had a peculiar watered-silk appearance, which it 

 was found impossible to represent on paper. 



On examination of teased preparations, it was evident 

 that the sections were cut obliquely, as the cells appeared 

 very much elongated; at the same time they showed no 

 reticulation. 



Sections from the same portion of the growth were 

 treated with osmic acid and several aniline dyes without 

 effect. I am, however, by no means skeptical as to the 

 results which ought to be obtained in perfectly fresh 

 specimens with chloride of gold. Its manipulation is 

 diflicult, owing to the nature of the tissue, changes in 

 temperature, light and color definition, therefore annoy- 

 ingly variable in its results. 



I cannot endorse Chatin's ^statement, as quoted by Dr. 

 Stokes on p. 374, No. 517 of this journal, that reticulated 

 structure in amoeboides and in the blood corpuscles of 



