But the vascularity of the dentinal pulp, and, especially, the
rich network of looped capillaries that adorns the formative peripheral
layer at the period of its functional activity, have attracted
Purkinje on the texture of dentine, which show that, if the pulp was converted at all, it must
be into a very different tissue from bone, and consequently by a different process from
ossification.
The nature of the process not having been discovered at that period, the formation of
dentine is described to be “ by the secretion of layers of dental substance/’ and the shell of
osseous substance so formed, is said to have 44 no organic connection with the matrix ; it is
formed by the deposition of the mineral components of the tooth mixed with some animal
matter, and may be lifted off its matrix,” (pp. 391 & 392).
So also Prof, de Blainville, in the fasciculus of his great work 44 Ostéographie d’Animaux
Vertebres,” submitted by him to the French Academy, on the same day on which I
communicated to that learned body, my 44 Theory of the development of dentine by centripetal
calcification of the pulp,” (December 16, 1839. See the 4 Compte Rendu’ of the Séance of
that day), says : 44 Pour bien comprendre la forme générale d’un phanéros,” (by this name the
Professor designates the class of organs called 4 teeth’) il faut savoir que c’est une partie morte
et produite, exhalée à la surface d’un bulbe producteur ou phanère, en continuité organique
avec le corps animal ; et implantée plus ou moins profondément dans le derme et même dans
les tissus sous-jacents ; et que, par conséquent, la forme du bulbe producteur détermine
rigoureusement celle du produit on du phanéros. Or, par la production seule des couches
de celui-ci appliquées successivement, en dedans les unes des autres, sur le bulbe producteur
seul vivant, seul lié par le système vasculaire et par le système nerveux au reste de
l’organisme, ce bulbe diminue de volume en même temps que de puissance productrice ; en
sorte qu’il arrive un moment où les cônes composants, ayant cessé de s’accroître en diamètre
avec le bulbe lui-même, commencent à diminuer avec hii.^^-Fascicule Premier, Primates, p. 15.
These formai expressions of well weighed ideas of the nature and formation of teeth, set
forth by the celebrated Professors of Berlin and Paris, afford the true indications of' the state
and the needs of that branch of physiology at the close of the year 1839. By only one writer
had the casual expression by Dr. Schwann, in his general Treatise on the Correspondance
between Animals and Plants in their structure and development, of his leaning towards the
old and exploded opinion, that the dental substance is the ossified pulp, been cited prior to
that date, in reference to the question of dental development. It occurs in the full Report of
the communications by Mr. Nasmyth to the * British Association’ at Birmingham, in August,
1839, in the 4 Literary Gazette’ of September 21st, 1839; and, as these 4 Communications’
betray a full knowledge of all that Schwann had published relative to the development of
general notice, and have been described by Hunter and subsequent
authors on Dental Development. By most this phenomenon has
been regarded as evidence of the secreting function of the surface
of the pulp, and the dentine as an out-pouring from that vascular
teeth, the conclusion to which Mr. Nasmyth had then arrived as to the formation of ivory
by ossification of the pulp,’ may afford some indication of the value of Schwann’s facts, and
the cogency of his observations in establishing that theory. It is true that Mr. Nasmyth has
formally denied, in his subsequent Communication to the French Academy, (Comptes Rendus,
Octobre, 1842, p. 680), that he had any knowledge of Schwann’s Treatise when he read his
Memoirs to the Meeting at Birmingham. Any one who may care to see to what extent
deliberate plagiarism from an original Author may be impudently attempted to be foisted
on the scientific public, as a record and evidence of original research, may compare the
‘ Report’ cited, with the observations, which occupy the whole of page 125 and part of the
preceding and succeeding pages of Schwann’s “ Mikroskopische Untersuchungen fiber die
Uebereinstimmung in der Struktur und dem Wachsthum der Thiere und Pflanzen, 8vo. 1839.”
The unacknowledged abstract fills more than a column of the 598th page of the Literary
Gazette (Sept. 21). From the passage beginning with “ According to Purkinje,’ and ending
with “ and of the dental bone,” the report of Mr. Nasmyth’s Memoir, excepting that where
Schwann asserts “ Mr. Nasmyth observes,” and that where Schwann believes “ Mr. Nasmyth
presumed;” is a coarsely literal translation of the German Author.
Some of the borrowed paragraphs might have excited a doubt, if rightly understood by
Mr. N., of the truth of the idea at that time maintained by him, of the formation of dentine
“ by the calcification of detached cells on the formative surface of the pulp,” or “ of the
deposition of the ivory by thin ossific layers on the surface of the pulp.” As, for example
Schwann, l. c. p, 125.
“ Diese in die Länge gezogenen kugel-
chen sind nun offenbar cylindrische
Zellen.”
“ Da sie auf der anderer Seite doch
mit der Zahnsubstanz fester Zusammenhängen
als mit der Pulpa, und an der
ersteren hängen bleiben so vermuthe ich,
das hier ein Uebergang statt findet.”
Literary Gazette, l, c. p. 598.
“ These longitudinally drawn out globules,
Mr. Nasmyth observed, are plainly
cylindrical cells ”—Also Medical Gazette,
Jan. 3rd, 1840, p. 540.
“ As they cohere more firmly with the
dental substance than with the pulp,
and remain attached to the former, Mr.
Nasmyth presumed that here a transition
takes place.”—Literary Gazette,l.c. p. 598,
and Medical Gazette. 1. c. p. 541.